Fix RANGECHECK on V_DrawPatch() functions, so the game exits with an
error at appropriate times.

Subversion-branch: /branches/v2-branch
Subversion-revision: 2692
Change netgame version mismatch message to be reminiscent of the Vanilla
message (thanks Alexandre Xavier).

Subversion-branch: /branches/v2-branch
Subversion-revision: 2693
Finish implementation of Hexen CD audio music mode.

Subversion-branch: /branches/v2-branch
Subversion-revision: 2694