#145737 by yhager, documentation cleaned up by myself: add support for RTL CSS overrides and default RTL CSS override files for modules
Note: properties, which are different in the RTL display are marked with /* LTR */ in default CSS files now,
so maintainers remember that changing them should also have an effect on RTL CSS files.

This should open the way for better RTL (right-to-left written) language (such as Arabic and Hebrew) support.

#128866 by myself: bjaspan noted that the pgsql and mysql updates on locale_update_6002() are reversed, I noted that the variables table got the language column inadvertently

- Patch #146313 by walkah: _user_edit_validate assumes arg(1) == 'register' when being called for the user_register form

#145748 by meba, after coding style fixes: disable the checkbox on the default language, so it cannot be disabled (the submit handler already disallows disabling it)

as a side effect, improve usability of the module screen by performing module
changes all at once

- Patch #144859 by dww: added optional e-mail notifications when user are approved, blocked, or deleted.

- Patch #105039 by ChrisKennedy: more polish for the custom date formats. Previous custom data format patch was also by Chris but got accidentically committed with another patch.  Thanks Chris.

#143249 by Jose A Reyero: add language parameter to t() to make it possible to retrieve translations of strings for different languages, to send emails to users in their own language for example

#141637 follow up patch by merlinofchaos: proper placement of menu_rebuild() to not run twice on the same request