[Gs-code-review] New test suite directory, framework, and documentation

[Jack Moffitt]

Overall (as I've said before) this is all good stuff.  A few comments:

- gsconf.py has lpd's personal configs in them (commented out).  I
  assume these won't get committed :)

- gscheck_all.py cannot be run standalone.


I would also like to propose a slight change.

I think that all tests that can be run standalone should be called
gscheck_*.py or check_*.py.  gscheck_*.py would be tests that invoke
ghostscript (right now these are in run_regression which would get
renamed to gscheck_compare? and my new pdfwrite tests might be
gscheck_pdfwrite). all the current gscheck scripts would be
renamed to check_*.py, since they don't invoke gs.

essentially a 'run_regression' script would then just add tests from
check_all.py and gscheck_all.py.

I think these changes would improve consistency even more.

jack.