plUruLauncher PatchOnly

Shhh! I'm sneaking this "feature" in for Gehn 18. The idea is that we
should no longer require MOULa installs for the installer to work. So,
after we've extracted the files but before we quit the installer, we fire
up `UruLauncher.exe -Repair -ServerIni=repair.ini -PatchOnly`. This will
download all the standard MOULa stuff, exit, and the install finishes.
Whew!