Merge branch 'twinxBugfix'
DOC: update ssl q in faq
handling zooming in panning in case of twinx

various changes to handle the default panning and zooming plugins when
having twin axes produces through twinx() or twiny()
pep8 related changes to test_twinx.py
twinxy test code

test_twinx generalised to also test twiny in a separate subplot
twins and twiny both handle zoom and pan correctly

various changes to make the zoom and pan work correctly for both twinx
and twiny
Add live PyPI stats to README file
pep8 and test related changes

code now passes pep8, nose test, and npm javascript.
pulled submodule updates
log file removed
fix minor typo in docstring

matplotliblib -> matplotlib
don't draw empty path collections

doing so causes a JavaScript error because "vertices is undefined".
add a test for empty line collections

test creates a figure with an empty line collection, which should be invalid but
is a reasonable accident to make and handle. It then ensures that a collection
with zero paths is not JSON serialised, because this would cause the JavaScript
to fail.
json serializer for numpy
TST: axis ticks with numpy dtype
TST: rename visual_test.py to visualize_tests.py

this matches the docs
update mplexporter submodule hash
Fixed mpld3.show() for Python 3.4 by calling encoding() on str
Added example plugin how to combine html elements with two-directional communication between IPython server and Javascript code
minor changes to slider plugin notebook