GtkDialog: disabled use-header-bar property untill Glade supports GtkHeaderBar
GtkAboutDialog: ignore construct only use-header-bar property to force it to False in the runtime.
Bumped gtk dependancy to 3.12
Fixed bug in numeric property editors
Restored widgets classes that do not fail anymore in gtk 3.12
Rolling 3.18.1
Add dialog to advertise user survey
Updated Polish translation
Update Spanish translation
Updated Indonesian translation
update zh_CN translation
Updated Lithuanian translation
Added few comments for translators
Updated Brazilian Portuguese translation
Updated Czech translation
Updated French translation
Updated Galician translations
Updated Russian translation
Updated Russian translation
[l10n] Updated Italian translation.