• Fix 0004017: Random translations popping up

  The language API has been cleaned up and simplified some.

  The problems with "random" translations were due to the fact that the language was changed temporarily for emails sent in a non-default language. If a page got refreshed during this send, it was diplayed in the wrong language. Now, the language API can hold more than one language at a time. And lang_get() has an optional additional parameter to specify which language a string should be returned in. That way the currently active language is not changed anymore.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2673 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9