Set up CacheManager as a Singleton.

Also changed function qa_private_translate_with_progress to
qa_recalc_progress_lang

From PRs by @pupi1985 (unmergeable due to file structure changes).
Closes #69.
Closes #126.

Allowed glob() to sort results

Set to Unix line endings in repo; the gitattributes file means they
will be converted to suit the user’s system.

Passed into theme and stored as boolean ‘isRTL’.