Move Torbutton translations to translations.git
The Torbutton translated strings from Transifex currently live in https://svn.torproject.org/svn/translation/trunk/projects/torbutton/po/.
I periodically have to run a pile of hokey scripts that convert to and from .po files and Mozilla DTD/properties files, causing the results to end up here: https://gitweb.torproject.org/torbutton.git/tree/master:/src/chrome/locale/
The scripts I use are here: https://gitweb.torproject.org/torbutton.git/tree/master:/trans_tools and how I use them is here: https://gitweb.torproject.org/torbutton.git/blob/master:/README.RELEASE#l20
Translators have reported that something about my conversion scripts causes some of their translated strings to suddenly disappear.
A direct route that doesn't involve any conversion to and from .po files would be preferable, especially if it means the only thing I ever need to update is the english versions of my DTD files, and then just copy the results from the translation.git repo into Torbutton.
Note that in addition to the existing Torbutton files, I am also about to add another dtd file for our new about:tor homepage (#7494 (closed)). If we could get this transition done before I add that dtd as a new .po file, that would be ideal.