[FEATURE] Add XLIFF translation support (l10n)

Add a parser to support XLIFF + LLXML file as localization file format.

This patch includes:

* A parser factory to support multiple internationalization formats
(actually LLXML and XLIFF, parser for PHP array is not implemented,
yet). New parsers can be added in the future.
* A new parser for XLIFF (supporting plurals, based on the parser of
FLOW3)
* Autoload for sysext 'lang'
* Update the existing localization method (FE, BE, Extbase) to support
the new format of the LOCAL_LANG array
* New caching class based on the caching framework or file based
* Autodetection igbinary for cache un/serialization
* htmlArea RTE: update of the localization API

Currently the localization method works as before (only key-based
localization).

More functionality will be implemented in the new localization API
(plurals, ...). The current parser can be used on a TYPO3 instance with
LLXML and/or XLIFF files. However if an extension uses XLIFF, the
language pack (typo3conf/l10n) MUST use the same format.

The parser and the format priority (by default: xlf, xml, php), can be
configured in $TYPO3_CONF_VARS['SYS']['lang'].

Change-Id: I84d0a463f1b5448b4bca3f7d200315f397f4ea18
Resolves: #25397
Reviewed-on: http://review.typo3.org/2572
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers