[TASK] Add clear l10n cache when the user clear all cache

Currently the l10n parser cache can only be cleared manually, by adding this in locallang.php:

$GLOBALS['TYPO3_CONF_VARS']['SYS']['lang']['cache']['clear_menu'] = TRUE;

This patch change the default behavior. By default the l10n cache is cleared on "clear all cache",
if the clear l10n menu item is enabled, it's not cleared on clear all cache.

Change-Id: I969a76d4a17ed847f39884883a887f4e0cb9c3a3
Fixes: #32600
Releases: 4.7, 4.6
Reviewed-on: http://review.typo3.org/7283
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter