shell-extensions: stop using g_settings_list_schemas()

This commit drops another use of g_settings_list_schemas

https://bugzilla.gnome.org/show_bug.cgi?id=720232
NEWS: update for release
configure: bump for release
Version 3.11.3

	* Warning fixes
	* Use modern methods for finding gsettings schemas
	* fail whale size request fixes
	* Translation updates
Updated Aragonese translation