Catch more variables errors

Display errors:
* when locale has extra variables
* when a variable is used a different number of times than reference
Fix import from Transvision+mozilla_org

Untranslated strings are identical to English, so we end up marking
strings as {ok}
Merge pull request #188 from flodolo/fix_import

Fix import from Transvision+mozilla_org
Merge pull request #187 from flodolo/python_errors

Catch more variables errors
Add firefox/android/index.lang and Privacy Tour

List of tracked locales is based on locales shipping in multilocale build on mozilla-aurora
https://hg.mozilla.org/releases/mozilla-aurora/file/default/mobile/android/locales/maemo-locales

List of locales for Privacy Tour is based on complete locales on last beta cycle
Merge pull request #189 from flodolo/android_page

Add firefox/android/index.lang and Privacy Tour
Android: add Albanian (sq)
Merge pull request #190 from flodolo/android_sq

Android: add Albanian (sq)