Core

[!!!][TASK] Move temp_CACHED_* files to caching framework

After the basic bootstrap refactoring that moved the loading of
ext_tables.php and ext_localconf.php to class context, it is now easily
possible to put the former temp_CACHED_* files to the caching framework
as cached PHP code, next to the autoloader registry cache entry.

This patch introduces a new API to t3lib_extMgm to handle the
loading of ext_localconf, ext_tables and the global TYPO3_LOADED_EXT
array and removes the current handling that was cluttered throughout
the core.

The setting of TYPO3_CONF_VARS['SYS']['extCache'] is now deprecated and
unused. The bootstrap now decides based on its context, whether caching
of those files is used. This way we can for example run the install tool
in a fully uncached environment and can get rid of the nasty side effects
we had in this area in the past.

With a simple call to t3lib_extMgm::removeCacheFiles() all cache entries
in PHP code cache that are tagged with 'core' can be removed at once.
This currently affects the autoloader registry, the TYPO3_LOADED_EXT
entry, and the concatenated ext_localconf and ext_tables files.

The patch furthermore gets rid of the _CACHEFILE array key in
$GLOBALS['TYPO3_LOADED_EXT'] that worked as a kind of API to the calling
method to indicate if a concatenated ext_tables and ext_localconf file
is available.

Change-Id: Id00be5f24ec1698ed9126e61b229a718d6ca6741
Resolves: #38414
Releases: 6.0
Reviewed-on: http://review.typo3.org/12383
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn