CodeIgniter 3 RC3

In addition to countless documentation improvements, here's a detailed list of the functional changes:

- Formally DEPRECATED 'global_xss_filtering'.
- Made some micro-optimizations.
- Added an $html_escape parameter to form helper set_value() (defaults to TRUE).
- Added CI_Input::$raw_input_stream as a read-only property (cached php://input contents).
- Changed CI_Input::$ip_address to be read-only.
- Allowed database connections to be created prior to controller instantiation.
- Removed 'autoinit' setting for database connections.
- Changed CI_URI to always default to using 'REQUEST_URI' and not to do URL-decoding on the data it has received.
- Changed set_status_header() function to be a dummy one under CLI.
- Added a 'sess_regenerate_destroy' config option.
- Changed time-based locks in session drivers ('redis', 'memcached') to be held for 5 minutes instead of 5 seconds, avoiding race conditions.

And bug fixes:

- Fixed a bug where session IDs were not regenerated (reported via the forums).
- Fixed a possible condition where session GC deletes sessions for another CI application that stores its session files in the same directory ('files' driver).
- Fixed a bug in session_destroy() for 'files' driver where it tried to delete a session that it hasn't yet created.
- Fixed an undefined variable notice in Session redis, memcached drivers when they're unable to obtain a lock.
- Fixed error logging for the session 'redis' driver when doing session_destroy() on a non-existing session.
- Fixed a bug in the Session library where it tried to force session.use_trans_sid to Off, but didn't due to a typo.

- Fixed a logical error in CI_Security::entity_decode() (no details about the effects it has caused).
- Fixed an issue in CI_Security::_remove_evil_attributes() where large inputs were completely invalidated instead of sanitized.

- Fixed a bug where CI_Config returned after loading the first configuration it finds.
- Fixed CI_DB_mssql_result::list_fields().
- Fixed CI_DB_pdo_driver::list_tables() where it always returned all tables with the 'dblib' and 'sqlsrv' drivers.
- Fixed a condition where CI_Email didn't conform to RFC2821 when ran under CLI.
- Fixed error logging in CI_Encryption for "invalid mode" conditions.
- Fixed FCPATH declaration under the condition that it is placed in directory named 'SELF'. *sigh*

We've also enabled unit test builds for PHP7-nightly, which are working fine ... we knew that anyway, just reassuring.