Updated Russian translation
Updated French translation
Updated Serbian translation
[l10n] Add Catalan translation
Updated Portuguese translation
Updated Danish translation
Updated Hungarian translation
Updated Slovenian translation
build: Use /usr/bin/env to find python

https://bugzilla.gnome.org/show_bug.cgi?id=726909
Work around for gdbus-codegen bug

https://bugzilla.gnome.org/show_bug.cgi?id=710133
Release version 3.12.0