[CM] cm ported to windows/sbcl

[Rick Taube]

svn sources has cm running in sbcl/windows. this necessitated a  
change to how *midi-player* is set on windows (its now stored as a  
unix style pathname in midi2.lisp) and for how shell works for clisp/ 
windows.  let me know if shelling in clisp stops working.

since both clisp and sbcl are now available options on windows the  
file "cm.bat" is now saved as either "cm-clisp.bat" or "cm-sbcl.bat"
--rick