Add back missing gm.dls for MIDI and add Procyon Pro (both Windows 3.1 and XP)

I uploaded a backup gm.dls in https://geocities.ws/devan/gm.dls - must be placed in C:\WINDOWS\System32\drivers

Install the MIDI sequencer Procyon Pro so that users are encouraged to making music on Pieter: https://archive.org/download/procyonpro/PROCYONP.ISO and/or https://archive.org/download/procyonpro/PROCPRO.ZIP