Fix some misc. Firefox compatibility bugs
Unify file transfer code into module.

This makes the code cleaner, and was also necessary since Firefox does
not support FileReader() being called inside a web worker.
Push git filename case change
Use helper to pack counter.

Wasn't available in the webworker.
Merge pull request #277 from arlolra/packctr

Use helper to pack counter.
Use strophe getUniqueId()

Wasn't available in webworker.
Merge pull request #279 from arlolra/unique

Use strophe getUniqueId()
File transfer download button now shows in Safari
Update Bengali translation
Use download attribute.
Merge pull request #284 from arlolra/filename

Use download attribute.
Add whitelist check for #284
Use data URI on Safari.
Merge pull request #285 from arlolra/safari

Use data URI on Safari.
Make Safari extension.
Merge pull request #286 from arlolra/safari

Make Safari extension.
Clean up strange buddy notification logic
Revert "Use data URI on Safari."

This reverts commit 54c50de0d617c48536fc82e0a7902027eeb53d20.
Bug fix
Revert "Clean up strange buddy notification logic"

This reverts commit 49f4a217d37a937528b914640eb03816aa8cd9c6.