Re: CG: add information about Regtest Checking Project (issue 5669047)

[graham]

http://codereview.appspot.com/5669047/diff/1/Documentation/contributor/regressions.itexi
File Documentation/contributor/regressions.itexi (right):

http://codereview.appspot.com/5669047/diff/1/Documentation/contributor/regressions.itexi#newcode511
Documentation/contributor/regressions.itexi:511: it shouldn't check
everything at once.  For example it's a bad idea to test
I disagree slightly here: most regtests should only do a single thing,
but a few (deliberately) test multiple ones.  For example, there's some
piece by IIRC Schubert which uses every type of grob (or something like
that; I just remember being told off by Jan for deleting that regtest so
I had to rescue it from git history).

Ideally those regtests would be clearly marked as separate from the
others, but since that hasn't been done, I don't think we should ask
users to complain about large regtests.

http://codereview.appspot.com/5669047/