[share] php memory performance for translations files

Well !

Found after a discussion on the french wp board something impressive.

WP does NOT USE the native gettext system so all translation files are loaded as PHP script SO it uses the limited php exec memory !!!!

This is a patch found on the track :

http://core.trac.wordpress.org/ticket/17268

BUT be carefull it cannot be used on all servers. Test it, but that could monsterly (this word exists ??) increase performance on translated WP installs specially multisites !