With the current wording users might expect aurutils to accept values
like "true". This change concretizes it to integers.

Concretize what aurutils sees as a positive value

Without this, the formatting of the AUR_PACMAN_BUILD environment
variable was incorrect.

This update fixes several bugs in sync-rebuild, and replaces the
aur-sync invocation with aur-fetch.

* Fix wrongly indented return statement in rebuild_packages(), causing
  at most one target to be handled
* Print package bases in diagnostic messages
* Use aur-fetch so that dependency order can be specified manually on
  the command-line, and no unneeded requests are spent on computing
  dependencies for repeated calls
* Update documentation

An alternative is to support both `aur-sync` and `aur-fetch`, replacing
`--no-fetch` (previously `--no-sync`) with `--sync` and `--fetch`,
respectively.

Since new dependencies need to be retrieved manually, this commit solves
issue #1139.

Add missing section header declaration to aur-build man page

examples/sync-rebuild: use aur-fetch

.SRCINFO files may contain CRLF. Since aur-graph cannot gracefully
handle these, preprocess the input with pacini(1).

Closes #1203

sync: preprocess .SRCINFO with pacini

#1210 (comment)

aur-build.1: example for setfacl

aur-fetch will not checkout new revisions by default.