* system-settings/src/nm-system-config-interface.c
	(nm_system_config_interface_supports_add): Implement.
	(nm_system_config_interface_add_connection): Return a boolean to notify
	of errors.

	* system-settings/src/nm-polkit-helpers.c:
	* system-settings/src/nm-polkit-helpers.h: Move error declarations to
	a separate file.

	* system-settings/src/dbus-settings.c (impl_settings_add_connection):
	Return an error when none of the plugins support add or if addition
	failed for some reason.

	* system-settings/src/nm-system-config-error.h:
	* system-settings/src/nm-system-config-error.c: New files, mostly moved
	here from nm-polkit-helpers.[ch].

	* system-settings/src/Makefile.am: Build new files.

	* system-settings/plugins/keyfile/reader.c
	(read_array_of_array_of_uint): Make it more general so that it would
	work for routes as well.

	* system-settings/plugins/keyfile/writer.c
	(write_array_of_array_of_uint): Ditto.
	Fix the netmask/prefix writing.

	* system-settings/plugins/keyfile/plugin.c (add_connection): Return
	boolean to notify errors.

	* system-settings/plugins/ifcfg-suse/nm-suse-connection.c (update):
	Return more specific error.
	(delete): Ditto.


git-svn-id: http://svn-archive.gnome.org/svn/NetworkManager/trunk@3821 4912f4e0-d625-0410-9fb7-b9a5a253dbdc