Stop offering Steam games as applications

Steam writes a desktop entry for every game somebody asks for a shortcut
to, and it starts the same program the client's own entry does:

    Exec=steam steam://rungameid/3527290

The scan only ever looked at the first token, found steam there, and filed
the game under the same kind as the client. So PEAK sat in the applications
list reading "on (Steam)", counted towards the applications covered, and
offered a space bar to switch it off again - as though it were something
this program had anything to offer. It is not: a game is whatever engine it
was built with, and none of them reads a Chromium argument.

An entry carrying a steam:// address of its own is not a program, it is one
more way of starting Steam. The client's own entry never has one - it takes
an address from the outside, through %U - and that is what tells the two
apart. Those entries go to the Steam module now instead of into the list.

They keep -noverifyfiles, for the same reason the rest of the Steam handling
has it: starting a game with the client closed is a Steam start like any
other, and without the switch it finds the patched web helper script, puts
its own copy back, and the interface loses autoscroll for the rest of the
session.

src/lib/apply.sh

@@ -107,6 +107,17 @@ mca_apply() {
 		mca_steam_apply
 	fi
 
+	# The shortcuts Steam writes for single games. They are not applications
+	# and are not offered as ones, but starting a game with Steam closed is a
+	# Steam start like any other: without the switch the client finds the
+	# patched helper script, puts its own back, and the interface loses
+	# autoscroll for the rest of the session.
+	if [[ $CFG_STEAM == yes ]]; then
+		for i in "${!MCA_STEAM_LINKS[@]}"; do
+			mca_steam_desktop_apply "${MCA_STEAM_LINKS[i]}" "${MCA_STEAM_LINK_FILES[i]}"
+		done
+	fi
+
 	# Steam's autostart entry carries Steam's own switch and follows the Steam
 	# setting, not this one - leaving it out while Steam is patched is what puts
 	# the client in an update loop - so both are checked inside.