Tests, Emacs-25 and Conditional Features

[Phillip Lord]

I have two questions about tests.

First, does the "no changes on Emacs-25" rule apply to changes in the
test directory -- i.e. can next tests be added. Arguments for -- tests
are a good thing to add and should not break a release. Arguments
against -- we are in pre-test, and it's easier to have a simple rule.
Also, tests are currently painful to merge.

Second, should tests assume that all the conditional features (gnutls,
libxml) are available? If the answer is no, then how can we test that
conditional features are present when they should be; if the answer is
yes, then do we want tests that will fail some of the time.

Phil