stat_function added
Tests updated for new testing framework
Merge pull request #170 from EricChiang/master

stat_function added
removed marker from geom_point aes, shape aes now works. addresses #154
Merge pull request #177 from funnell/geom_point_shape

removed marker from geom_point aes, shape aes now works. addresses #154
DOC: add doc requirements for readthedocs

Also add numpy to require in setup.py at the *last* position
so that installs on readthedocs.org work *before* all other
packages and move statsmodels to the first position
(-> installed last) so that stasmodels can be installed when
ggplots "python setup.py install" is run.
DOC: fix contributing documentation

code in contributing.rst doe snot need to be executed, as it
is exmaples of a new geom. So stop that :-)
todo: mark some of the items as inplemented
DOC: print plots in docstring examples