DEP: deprecate scipy.weave in favor of https://github.com/scipy/weave

And in favor of Cython for new code of course.

Closes gh-3171.
TST: disable slow weave tests for weave.test('full').  Fix TravisCI timeouts.

The slow weave tests will be run if an environment variable RUN_WEAVE_TESTS
is set to True.

Closes gh-3318.
Merge pull request #3640 from rgommers/deprecate-weave

Weave: deprecate the module and disable slow tests on TravisCI