add path rendering
add collection exports
add draw_image
add zorder to element styles
add mplobj to renderers
add axis properties to exporter
fix data coordinate processing
PEP8 + Rearrange names in exporter
add some documentation
Subplot in PlotlyRenderer is more functional. Two utils functions added.

Previously, PlotlyRenderer would count the number of subplots and simply
make a column of them, equally spaced. It now uses the axes bounds to
exactly copy axes placement. Note, test objects are only copied
currently as strings, so formatting still changes upon import into
Plotly.

Two simple functions are added to the plotly_utils.py file to extract x
and y domain information from the axes bounds: (x0, y0, width, height)
to [x0, x1], [y0, y1].
Better test function and nicer looking example for subplots.

The test function in the 'tests' dir now uses a custom function for
comparing two dictionaries which outputs the exact dictionary entry upon
a comparison failure. This is used as a message for the assertions so
that errors can be found quickly.

Example for subplots now uses matplotlib.gridspec and includes extra
'wspace' and 'hspace' so that the resulting plot ticks can be clearly
seen. It shows how complicated subplot structures can be ported to
Plotly.
Added subplot example to plotly ipython notebook.

That's all folks.
Merge remote-tracking branch 'mpld3/master'

Conflicts:
	mplexporter/renderers/plotly/plotly_renderer.py

Added mplobj keyword argument to Plotly Renderer
Commit after adding mplobj keyword args to PloltyRenderer.
Merge branch 'renderer'
Merge branch 'ipynb'

Conflicts:
	notebooks/PlotlyTest.ipynb
Updated IPython notebook for plotly.