* set NM to a usable value.
* provide for invoker-supplied TEST_JSON_CFLAGS.
* add feature flags `NO_ADDR_BITMASK_MATCHING` and `NO_IPV6`.
* rename feature flag `NO_STDIO` to `NO_STDIO_STREAMS`.
* allow override for TEST_JSON_CFLAGS.
* in doc recipes, use -L flag to cp to force early failure for missing files.

Makefile.analyzers:
* rename no-stdio-build-test to no-stdio-streams-build-test.
* in minimal-threaded-build-test recipe, change -DWOLFSENTRY_USE_NONPOSIX_SEMAPHORES to -DWOLFSENTRY_NO_SEM_BUILTIN.
* add targets library-dependency-singlethreaded-build-test, library-dependency-multithreaded-build-test, no-addr-bitmask-matching-test, no-ipv6-test, linux-lwip-test-no-ipv6.
* raise WOLFSENTRY_MAX_CYCLES_PER_CALL_JSON_LOADED in benchmark-test and benchmark-singlethreaded-test recipes, to accommodate additional overhead from bitmask matching logic.
* fix default FREERTOS_TOP_FOR_TEST to have $(SRC_TOP)/ prefix.
* refactor freertos-arm32-build-test to include final link of test_lwip kernel, and check on size of kernel.
* split LWIP_SRC_LIST into LWIP_SRC_LIST_BASE, LWIP_SRC_LIST_UNIX, and LWIP_SRC_LIST_FREERTOS, add FREERTOS_SRC_LIST, and add recipes for compiling FreeRTOS sources (needed by refactored freertos-arm32-build-test).

README.md: rename NO_STDIO to NO_STDIO_STREAMS, and add docs for WOLFSENTRY_NO_STDIO_H, NO_ADDR_BITMASK_MATCHING/WOLFSENTRY_NO_ADDR_BITMASK_MATCHING, NO_IPV6/WOLFSENTRY_NO_IPV6, and WOLFSENTRY_NO_SEM_BUILTIN.

doc/json_configuration.md: add documentation and ABNF grammar for "bitmask" node in route endpoints.

ports/FreeRTOS-lwIP/include/arch/cc.h: copy inet_ntop and inet_pton definitions from ports/Linux-lwIP/include/arch/cc.h.

ports/FreeRTOS-lwIP/include/arch/sys_arch.h: add file.

ports/FreeRTOS-lwIP/include/lwipopts.h: synchronize with ports/Linux-lwIP/include/lwipopts.h.

ports/Linux-lwIP/include/lwipopts.h: allow override definition of LWIP_IPV6, and set LWIP_ICMP6 to LWIP_IPV6, to allow disabling IPv6.

wolfsentry/wolfsentry.h:
* bump version to 1.6.0.
* add WOLFSENTRY_ACTION_RES_USER0-WOLFSENTRY_ACTION_RES_USER6 to wolfsentry_action_res_t enum, add WOLFSENTRY_ACTION_RES_USER7 macro, and refactor WOLFSENTRY_ACTION_RES_USER_BASE as a macro aliased to WOLFSENTRY_ACTION_RES_USER0.
* add WOLFSENTRY_ROUTE_FLAG_REMOTE_ADDR_BITMASK and WOLFSENTRY_ROUTE_FLAG_LOCAL_ADDR_BITMASK to wolfsentry_route_flags_t.
* remove !WOLFSENTRY_NO_STDIO gate around wolfsentry_kv_render_value().

wolfsentry/wolfsentry_errcodes.h: add WOLFSENTRY_ERROR_ID_WRONG_ATTRIBUTES.

src/wolfsentry_internal.h:
* add wolfsentry_table_reset_fn_t and wolfsentry_coupled_ent_fn_t, and add reset_fn and coupled_ent_fn to struct wolfsentry_table_header.
* add last_af_wildcard_route to struct wolfsentry_route_table.
* add n_bitmask_matching_afs and bitmask_matching_afs[] to struct wolfsentry_route_table, gated on WOLFSENTRY_ADDR_BITMASK_MATCHING.
* add wolfsentry_table_cursor_set() inline implementation.

wolfsentry/wolfsentry_settings.h:
* rename WOLFSENTRY_NO_STDIO to WOLFSENTRY_NO_STDIO_STREAMS.
* rename WOLFSENTRY_HAVE_NONGNU_ATOMICS to WOLFSENTRY_NO_GNU_ATOMICS.
* add handling for WOLFSENTRY_NO_SEM_BUILTIN, WOLFSENTRY_NO_ADDR_BITMASK_MATCHING, and WOLFSENTRY_NO_IPV6.
* gate inclusion of stdio.h on !WOLFSENTRY_NO_STDIO_H, formerly !WOLFSENTRY_NO_STDIO.
* eliminate inclusion of errno.h -- now included only in source files that need it.
* fix handling for WOLFSENTRY_SEMAPHORE_INCLUDE to give it effect in all code paths (previously ignored in POSIX and FreeRTOS paths).
* add WOLFSENTRY_CONFIG_FLAG_ADDR_BITMASKS, and rename WOLFSENTRY_CONFIG_FLAG_NO_STDIO to WOLFSENTRY_CONFIG_FLAG_NO_STDIO_STREAMS.

src/addr_families.c and wolfsentry/wolfsentry_af.h:
* split WOLFSENTRY_AF_LINK into WOLFSENTRY_AF_LINK48 and WOLFSENTRY_AF_LINK64, with WOLFSENTRY_AF_LINK aliased to WOLFSENTRY_AF_LINK48.
* handle WOLFSENTRY_AF_CAN in wolfsentry_addr_family_max_addr_bits_1().
* add wolfsentry_addr_family_get_coupled_ent()

src/kv.c: remove !WOLFSENTRY_NO_STDIO gate around wolfsentry_kv_render_value().

src/routes.c:
* rename cmp_addrs() to cmp_addrs_prefixful().
* add is_bitmask_matching(), wolfsentry_bitmask_matching_upref(), wolfsentry_bitmask_matching_downref(), cmp_addrs_bitmaskful(), and addr_bitmask_match_size(), and integrate them into wolfsentry_route_key_cmp_1() and compare_match_exactness(), pivoting on WOLFSENTRY_ROUTE_FLAG_REMOTE_ADDR_BITMASK and WOLFSENTRY_ROUTE_FLAG_LOCAL_ADDR_BITMASK.
* add bitmask handling and .last_af_wildcard_route accounting to wolfsentry_route_init(), wolfsentry_route_init_by_exports(), wolfsentry_route_new(), wolfsentry_route_new_by_exports(), wolfsentry_route_insert_1(), and wolfsentry_route_delete_0().
* add bitmask handling and AF-mismatch optimization to wolfsentry_route_lookup_0().
* in wolfsentry_route_event_dispatch_0(), move update of meta.purge_after inside the mutex.
* in wolfsentry_route_get_metadata(), conditionalize use of 64 bit WOLFSENTRY_ATOMIC_LOAD() on pointer size, to avoid dependency on library implementation of __atomic_load_8().
* add WOLFSENTRY_AF_CAN support to wolfsentry_route_format_address() and wolfsentry_route_render_address().
* add bitmask support to wolfsentry_route_format_json(), wolfsentry_route_render_flags(), and wolfsentry_route_render_endpoint().
* add wolfsentry_route_table_reset().

src/wolfsentry_internal.c:
* add .last_af_wildcard_route accounting to wolfsentry_table_clone().
* fix use-after-free bug in wolfsentry_table_free_ents(), using new table->coupled_ent_fn mechanism.

src/wolfsentry_util.c: implement support for WOLFSENTRY_SEM_BUILTINS gate.

tests/test-config*.json: add several bitmask-matched routes, and add no-bitmasks and no-ipv6 variants.

tests/unittests.c:
* additional tweaks for portability to 32 bit FreeRTOS
* add FreeRTOS-specific implementations of test_lwip() and main().
* in test_json(), add wolfsentry_addr_family_handler_install(...,"my_AF2",...).
* in test_json(), add bitmask tests.
* add stub implementations for various FreeRTOS/newlib dependencies.

src/json/load_config.c:
* gate on !WOLFSENTRY_NO_ERRNO_H uses of errno to check for errors from strtol() and friends (fall back to testing for incomplete parsing of data).
* in convert_sockaddr_address()
  * add separate handling for WOLFSENTRY_AF_LINK48 and WOLFSENTRY_AF_LINK64.
  * add handling for WOLFSENTRY_AF_CAN.
  * add JSON type checking -- WOLFSENTRY_AF_CAN addresses can be native JSON numbers.
  * add a separate sa_addr arg, allowing the caller to designate an offset address for output (used to build bitmask addresses).
  * handle sa->addr_len consistently -- don't overwrite nonzero values.
* in handle_route_endpoint_clause() add handling for bitmasks.

src/json/{centijson_dom.c,centijson_sax.c,centijson_value.c}: eliminate direct calls to heap allocator functions in WOLFSENTRY code paths, i.e. use only wolfsentry_allocator.

src/json/centijson_value.c: fix uninited-variable defect on cmp in json_value_dict_get_or_add_().

…NTRY_ROUTE_FLAG_{REMOTE,LOCAL}_ADDR_BITMASK.

src/json/centijson_sax.c: give the automaton enum a name, and change json_switch_automaton() to take an enum centijson_automaton to fix a conversion error on MacOSX clang-14.