i18n 6.x-1.0-beta4

Many bug fixes and some polishing:
- Fixed issue with language dependent front page, that couldn't be used before
- Fixed postgresql compatibility issue, by miopa, #308554
- Fixed profile category string issues, #304451
- Renamed some modules, updated descriptions
- Fixed / improved some module help texts.
- Fixed multiple localization issues, by hass, #310852
- Fixed error with i18ncontent update, #295263
- Fixed warning in sync module, by vjacquin, #299064 and #294511
- Fixed issue with i18nblocks and system module weights, #299642
- Fixed warning in i18ntaxonomy, by mvc , #304003