new pretest folder

I moved a bunch of .pr files from pr/test to a new pr/pretest.  These are
test files, some new, some old, that don't yet give a clear good/bad report
when run.  These should also be used when testing for release but they
should only be checked for reasonable output and lack of crashing.

Test files in pr/pretest should be considered to-do items to be turned into
real test files to be moved into pr/test.