ACL6 support



Support for ACL6 has been checked in.  I tested the result with Clisp, 
Gcl, and CMUCL, and all tests passed as expected.  ACL6 also passes the 
tests too.


I think most of the changes are specific to ACL6, but some impact others:

o Changed MAKE-NUMBER to read everything in as a double-float.  Numbers 
like 1e20 were getting read as single-float, which is probably not what 
we want.

o SWAP-ROWS is commented out for ACL6 until I figure out what (STORE 
(MELT ...) ...) is supposed to do.

o Xmaxima does not work.

o You can not split input across multiple lines like the other lisps. 
All input must be on one line, including the semi-colon.

I think this will also work on windows if you do something cd to the src 
directory, load ../lisp-utils/defsystem, (mk:oos "maxima" :compile).

I looked a bit at licensing as well.  It appears that it is perfectly 
acceptable to distribute the fasl files because you can only run these 
if you're already licensed.  Can't distribute a dxl file because that 
might give you access to things you're not licensed for.

All in all, acl6 works nicely.

Ray