Make Cython modules work with doctest

[dagss]

A new directive "autotestdict" (might default to True unless opposition appears on ML). When enabled, *and* a __test__ dictionary is not already present, one is created containing all functions and methods with docstrings in the file, so that they get picked up by doctest.

 http://thread.gmane.org/gmane.comp.python.cython.devel/7626

[dagss]

 http://hg.cython.org/cython-unstable/rev/6371ba048f68  http://hg.cython.org/cython-unstable/rev/7e2cbc8f78ac

I'll also make it the default in an upcoming changeset.

[dagss]

There's a problem with cdef functions getting picked up, reopening (it's not turned on by default so no problem).

[dagss]

OK this is done now. The directive is renamed to autotestdict.

[dagss]

A new approach is needed; not all slots in cdef classes are available from Python space.

The best solution is probably:

1. Generate __linenumbers__ dict statically
2. Insert code in module startup to build __test__ dynamically from dir() and __linenumbers__.

This is much easier to do once CythonUtilityCode? is merged, which makes it more suitable for 0.12.1.

It could be turned off by default until that can be done if this is too much of an issue.

This hack ( http://hg.cython.org/cython-devel/rev/48ab4c8c76d1) should at least get Sage to compile, I think, but it is not even complete with regards to slot names.

[dagss]

I guess the issue of whether it should be default should be revisited before pushing the ticket to 0.12.1.

[dagss]

The blacklist has seen some more work/modifications and should be rather safe. We rather quickly started to depend on this feature (both in our tests and in my personal project code) so this should probably be left on by default for 0.12. Moving to 0.12.1 to revisit the question of the best implementation.

[dagss]

On second thought, I'm opening a new ticket for improvement so that this gets into release history...

[dagss]

Follow-up on #497