Remove Mac OS interface.
Remove bin/ugkillall.

ugkillall tries to do what the killall command on Linux already
provides. It probably is no longer of much use nowadays.
Remove several scripts for old build system.
Remove copies of LaTeX style sheets.

These files can be found as part of LaTeX, for example in Debian in
the latex209-base package. There is no need to include a copy in UG.