avatar-chooser: split creation of the file chooser dialog
avatar-chooser: split creation of the file chooser dialog

https://bugzilla.gnome.org/show_bug.cgi?id=652985

Distrotech/telepathy-account-widgets,GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets