Log Message:
Update to 0.21:

NEW in 0.21:
============

Updated translations: hi, ar, it, sr, sr@latin, pt.

Many thanks to the translators: Rajesh Ranjan, Djihed Afifi, Luca
Ferretti, Goran Rakić, Duarte Loreto, Francesco Marletta, Khaled
Hosny.

NEW in 0.20:
============

- Fixed #499050, fix build against xulrunner 1.9 (Josselin Mouette)
- Fixed #537093, Does not build with gcc 4.3.0 (Cosimo Cecchi)
- Fixed #539624, Crashes when copying text with xulrunner 1.9 (Claudio Saavedra)
- Updated translations: vi, kn, sr, or, mr

Many thanks to the translators: Clytie Siddall, Shankar Prasad, Goran
Rakic, Manoj Kumar Giri, Sandeep Shedmake.