Update Git ignores.
Update Git ignores.

Apparently I forgot to consider the the top-level '.gitignore' when
splitting up the repo (I didn't do 'ls -a' at the top level :P).

GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script