Fixes #1167 and fixes #1168

This lets us use the natural location for .coveragerc

By not actually recording anything for the tests. Presumably because they're executed as scripts, not as gevent.tests.whatever.

Travis is reporting src/gevent/test__* as uncovered, for some reason, but I don't get that locally.

Need to use an editable install on appveyor to find our test files; should probably loosen that restriction for downstream [skip travis]

In preperation for its removal.

Fixes #1305.

Write modified module source to a tempfile so we get correct tracebacks.

See https://ci.appveyor.com/project/denik/gevent/builds/20122331/job/9uowlkm47ayqwkxx#L1800

Fixes #1306

There's probably some sort of performance penalty, but we don't run all that many monkey files (22 or so), and they take long enough that I suspect its lost in the overhead.

Find greenlets in Cython code, keeping the GIL.