reportbug-ng has localization support again

After having ported reportbug-ng from PyQt3 to PyQt4 over a year ago, reportbug-ng lost it's localization, since the gettext based translations where incompatible with Qt4's translation system.

This weekend I finally had the time to have a closer look at this problem. To make a long story short: I have ported the gettext based system to Qt4's system. All the old .po files where converted to .ts files, but almost all strings are marked as "obsolete" so that they don't appear in the translated program. But since they are still available in the .ts file, it is easy to get the translations up-to-date. So far only English and German are complete, but eventually other translations will be added.

PyQt4 makes it by the way really hard to get non-Qt strings translated.