[Unix-jun72] slight tools cleanup

[Tim Newsham]

I reorganized the build process slightly.  Hopefully this won't affect
anyone and everything will keep working as before.   I basically
took the 'sed' hacks out of assemv7 and made the "rebuild" script do
the patching with proper patch files instead.  There is now a patches
directory with all of the patches we are using and comments on what
they do and why.

Tim Newsham
http://www.thenewsh.com/~newsham/