Remove obsolete .cvs ignore files.

Remove obsolete .cvs ignore files.

* .cvsignore, doc/.cvsignore, libltdl/.cvsignore,
libltdl/config/.cvsignore, libltdl/loaders/.cvsignore,
libltdl/m4/.cvsignore, tests/.cvsignore,
tests/cdemo/.cvsignore, tests/demo/.cvsignore,
tests/depdemo/l1/.cvsignore, tests/depdemo/l2/.cvsignore,
tests/depdemo/l3/.cvsignore, tests/depdemo/l4/.cvsignore,
tests/f77demo/.cvsignore, tests/fcdemo/.cvsignore,
tests/mdemo/.cvsignore, tests/mdemo2/.cvsignore,
tests/pdemo/.cvsignore, tests/tagdemo/.cvsignore: Deleted. Even
when using savannah's CVS readonly mirror there's no way to commit
back to the real repo, so this files are not worth maintaining
or keeping around.