i18n 6.x-1.0-beta6

Fixed update bugs in previous beta5
Changelog from beta5:
- Fixed multilingual blocks not translating, #305868
- Fixed notices, undefined variables, by eMPee584, #276161
- Fixed some issues with strings and menu install/updates
- Fixed typo in i18nblocks_update_2(), #317042
- Fixed warning illegal offset type, #294278
- Removed wrong version from info files, by Roger López, #319249
- Fixed help string, by Hass, #316784
- Uncountable code style issues have been fixed for coder module compliance and core rules.
- Fixed: Translation issues like missing periods, typos, etc.
- Fixed: Synchronization not happening when creating a translation, #313605
- Added some help texts for i18nstrings and warnings about the site default language, #314035
- Fixed: Column name conflict (oid) on PostgreSQL, #314126
- Fixed: Added English language to import/export page, #314035
- Fixed: Code tries to access object as array, by Skiller, #293275
- Fixed: Sub-menu items not localized, by Anselm Heaton, #298612
- Some clean up in i18ntaxonomy module, coding standards, cvs tags, etc..
- Fixed some race condition when creating term translations
- Multiple bug fixes and code improvements, by stella, #314846, #314880, #314853