TYPO3 Core

Except to a database structure change of the experimintal PDO backend all
changes are backwards compatible for existing extensions usages if the
current API was not misused.

otable changes:
- A new "context" variable for backends constructors was introduced. In v4 it
is always set to "production" in production environment and to "Testing" for
unit tests. Other than that it is unused and was ported to keep v4 and
FLOW3 in sync.
- File backend now uses different directories for a code and data caches.
- Files created by the file backend have a .php suffix for code caches.
- In file backend, FLOW3 removed the cacheDirectory() method. It is kept
for v4 to enable us to have cache directories outside of the document root.
- File backend unit tests use vfs (virtual file system). This way no more
persisted files are created by unit tests in the file system that must be
cleaned up afterwards.
- t3lib_cache_Manager has a new method injectCacheFactory(), used by
t3lib_cache_Factory. t3lib_cache, tslib_fe and init.php reflect this change.
- t3lib_cache_Factory calls initializeObject() of frontends and backends if the
method exists. Some __construct() calls are moved to this method.
- Some code and unit tests now use name spacing for global objects.
- t3lib_cache_Manager has new protected methods to call all configured caches
on flushCaches() and flushCachesByTag(). Its usage in v4 will be enabled with
a separate patch.
- Pdo backend changed its database structure and uses a "context" field instead
of "scope" now.
- Lots of minor variable renamings, comment changes and annotation fixes.