Better translation making, and add zh_Hant
Put translations into app resource instead

This eliminate the need of using external paths for .qm files, and
can be used unmodified between all platforms.

By putting two entries of zh_TW in .qrc and aliasing one of them
to zh_TW.UTF_8 we also eliminate the problem caused by erroneous
locale names on LilyTerm, fixing #57.