xtermset THANKS file

xtermset has originally been written by Breyten J. Ernsting.
Many people have further contributed to xtermset by reporting problems, 
suggesting various improvements, or submitting actual code. Here is
a list of these people. Help me keep it complete and exempt of errors.

Sam Lantinga (slouken@cs.ucdavis.edu)
Decklin Foster (decklin@red-bean.com)
