Updating translation files (with a few minor corrections to string formatting arguments). Improving test_translations.py script, which helps me detect problems with missing formatting args. Fixed an issue preventing the track names from being translated on launch.

Adding lock feature to tracks, which prevents clips from being moved or resized (or added), however properties can still be manually edited, and context menus still accessed. So, more of a partial lock. Updated all language translations and the POT template.

Updating translations from launchpad. I also tested the top 50 languages, and fixed a few things in both these PO files, and launchpad (so it won't break on the next update).

Updating translations to newest Launchpad.net versions. Also fixed a few translation issues upstream (in LaunchPad) as well... missing string replacement symbols %s

Fixing lots of translation issues (i.e missing translations, unneeded contexts, duplicates in UI files). Also updated the translation files to the most recent version from Launchpad.