colormap: Fix generated COLORMAP size.

In this old Doomworld thread, shadow1013 pointed out that some tools,
such as SLADE, do not recognize COLORMAP lumps unless they are
exactly the right size:
http://www.doomworld.com/vb/freedoom/58317-colormap-generation-bug/
patches: Restore original wall62_2 patch.

commit ddb0c98a44eb30feb4b9 (a long, long time ago) changed the
wall62_2 patch to a new version that was supposedly better. But
really it is much worse: the colors just look washed out and ugly.
Restore the original version of this patch from before the change.
Use print() for Python 3 compatibility.

This doesn't get everything working in Python 3 yet but it's a
start.
levels: Add UDMX levels maps for FreeDM.

deathz0r posted these on Doomworld a long time ago (2006) but they
were never picked up. Add them now as DM26, 29 and 30, and move the
current unfinished DM29 to DM33.