Fix bug 5176 (Theme descriptions not translated).

	Fix bug 5187 (Real name in file ownership doesn't take GECOS data
	into account).

	* src/nautilus-theme-selector.c: (make_theme_description): Get the
	theme description (which I also moved to the theme node from its
	own description node) by using
	nautilus_xml_get_property_translated which handles using the
	gettext database to translate the property if the XML file has it
	with a _ prefix.

	* icons/ardmore/ardmore.xml:
	* icons/arlo/arlo.xml:
	* icons/default.xml:
	* icons/gnome/gnome.xml:
	* icons/vector/vector.xml:
	Moved description to be a property of the theme node and use the
	name that indicates it needs to be localized.

	* po/POTFILES.in: Add all of the theme .xml files which now
	potentially have localizable theme descriptions in them.

	* libnautilus-extensions/nautilus-file.c: (get_real_name): Add
	code to compute the real name from the GECOS info, by stripping
	anything after the "," and substituting the login name,
	capitalized, for any occurences of "&".
	(get_user_and_real_name_from_id): Use get_real_name instead of
	going for the pw_gecos field directly.
	(nautilus_get_user_names): Use get_real_name instead of
	going for the pw_gecos field directly.

	* libnautilus-extensions/nautilus-string.h:
	* libnautilus-extensions/nautilus-string.c:
	(nautilus_str_strip_substring_and_after),
	(nautilus_str_replace_substring), (nautilus_self_check_string):
	Add two new string utility functions and self-checks for them.
	These were both needed for the GECOS change.

	* src/nautilus-property-browser.c: Tweak formatting.