Serbian translations update/fix

Closes #730
Use different network cache folders for each WebKit version

Fixed crashes when using cache from older QtWebKit in 2.3 version
GreaseMonkey: Reload scripts on when source file changes.

Closes #729
Merge remote-tracking branch 'upstream/master'

Conflicts:
	translations/sr_BA.ts
	translations/sr_BA@latin.ts
	translations/sr_RS.ts
	translations/sr_RS@latin.ts