FreshRSS/simplepie#23
And additional fixes

* rename lib/SimplePie to lib/CustomSimplePie

* add test for autoloading SimplePie with PSR-0

* install SimplePie 1.6.0

* Add SimplePie CHANGELOG.md, ignore irrelevant files

* remove unmodified custom classes

* rename all customized SimplePie classes

* Add autoloading for SimplePie PSR-0 and CustomSimplePie classes

* let CustomSimplePie extends SimplePie, remove unchanged code

* let CustomSimplePieMisc extends SimplePie\Misc, remove unchanged code

* Add tests for autoloading

* let CustomSimplePieContentTypeSniffer extends Sniffer, remove unchanged code

* remove unchanged CustomSimplePieEnclosure class

The fixed typos are commited to SimplePie
See simplepie/simplepie@133eac1

* let CustomSimplePieFile extends SimplePie\File, remove unchanged code

* let CustomSimplePieParser extends SimplePie\Parser, remove unchanged code

* let CustomSimplePieSanitize extends SimplePie\Sanitize, remove unchanged code

* let CustomSimplePieHttpParser extends SimplePie\HTTP\Parser, remove unchanged code

* Remove CustomSimplePie

* Switch SimplePie repo to https://github.com/FreshRSS/simplepie.git

* move to latest branch, update all SimplePie source files

* Use namespaced SimplePie classes, remove SimplePie library folder

* Update to latest SimplePie version with FreshRSS modifications

* Bump SimplePie
Tests expected to fail due to missing a backport of functionalities

* Add fork-specific readme

* Re-implement initial syslog SimplePie GET
#815
Lacks #6061

* Closer backport of syslog SimplePie GET
#6061
But the requests logs will be in the wrong order in case of redirections

* Fixes

* lib update

* SimplePie include a few more files

* Try with cache-hash branch

* Point to newer commit

* Point to newer commit

* Finalise logs

* Finalise

* Bump SimplePie commit

* Bump SimplePie commit

* Readme SimplePie fork

* Bump SimplePie commit

* Better logging

* Bump SimplePie commit

* Reworked approach to work with SimplePie cache
Simpler FreshRSS patches

* Bump SimplePie commit
FreshRSS/simplepie#22

* Simplepie846
FreshRSS/simplepie#23
And additional fixes

* Remove log

* Cherry pick relevant unmerged SimplePie PRs

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Co-authored-by: Alexandre Alapetite <alexandre@alapetite.fr>