Update master port to emacs21.
Update slave ports to stub port: semi-emacs20, semi-xemacs21-mule.
Does not support semi-emacs(19) and semi-mule for semi-1.14.x or later.
Change some style.
- Remove *-setupel.el routines and scripts/configure.
Because Emacs20 or later has subdirs.el.
- Specify PREFIX, LISPDIR, and VERSION_SPECIFIC_LISPDIR clearly
when port building.
- Install *.el{,c} files to version specific site-lisp directory.