tcsh: cleanup source tree to reduce diff size.

tcsh: cleanup source tree to reduce diff size.

Remove makefiles, configure files and unused at build time files
to reduce the diff size. Otherwise the diff contains a lot of
unnecessary lines what makes reviewing and merging proccess so hard,
especially for re@.

(cherry picked from commit 6190ff6104aed4cd753019325a252c4d66495b5e)