update .gitignore for docs and pycharm
TST: shorten long running test
Small fixes in manual tests
Add possibility to specify dataframe and aes per geom

This makes it possible to specify `geom(data=df, aes=aes(...))`. This
needed a bigger refactoring for the methods which manipulated the
underlying data.

Also adds a basic tests for this functionality.
Add __ALL__ to all relevant files

This makes `from ggplot import *` cleaner, not cluttering the namespace
with other imported names.
DOC: New documentation system based on numpydoc

The system is stolen from pandas and the current docs are changed
so that they fit into the new doc system.
DOC: Update gitignore with documentation changes
DOC: Make existing docstrings numpydoc compatible
DOC: Use source instead of installed version
Add ggplot.__version__ and use it in setup & docs
Merge pull request #124 from JanSchulz/geom-data

Geom data
Merge pull request #109 from JanSchulz/contributing_additions

Documentation building and some doc additions
adding example
inc version for minor revision
Added minor grid lines to plots, tweaks to theme_gray
updating test baseline images to reflect updated theme_gray
updated readme images to reflect changes to theme_gray
remove depricated file
Merge pull request #126 from funnell/minor-grid

Minor grid to theme_gray
Merge pull request #127 from wooparadog/master

Remove depricated file.