Merge remote-tracking branch 'upstream/master'
Catch numdifftools import error
Merge pull request #387 from msmbuilder/feature/catch-import

Catch numdifftools import error
Load plugins from entry point
Add description of plugins to docs
Make sphinxext py3 compatible

Note that the example notebooks are not py3 compatible
so there is still work to be done!
add install faq question for issue #391
Merge pull request #395 from msmbuilder/doc-cython

add install faq question for issue #391
Use explicit python syntax highlighting
Merge pull request #396 from mpharrigan/plugins

Plugins
Add test for tICA from https://github.com/msmbuilder/msmbuilder/pull/394#issuecomment-66224420
Merge pull request #398 from msmbuilder/feature/tica-test

Add another test for tICA GMRQ
spline
Merge pull request #403 from msmbuilder/spline

[MAINT] Von-Mises spline
Sparse tICA greedy mode
Some tests
tests for the three code paths with no sparse eigenvectors
one more
Add experimental flag
add one sparse tica test