Backport file-roller to support rar

Hi, i have packported the file-roller package from the file-roller raring sources and they have worked fine.

At file-roller 3.7.1 the rar (unar) support is complete.

The file-roller at raring is 3.6.3, there are 2 bugs open until 3.7.1, the latest 3.10 file-roller needs GTK 3.10, but 3.6.3 uses GTK 3.4 so is compatible.

Maybe we could backport those changes to Toutatis, so user could use unar along with file-roller improving the rar support.

Cheers!