Gabriel Knight 1: 1.6.2-dos_support_0.6, SBPro music

1.6.2 may be fixing some bugs with GOG installer? (#3735)

While installing a MIDI synthesizer program may lead to better results,
its requirement is not obvious enough; SoundBlaster Pro music by default
is just simpler on the users.
Added Ultima 4+5+6 (contributed by Daemonburrito)