add wordcloud chart
add word cloud js to ipython notebook
add word demo to ipython notebook example
removed and ignored .ipynb_checkpoints
Merge pull request #88 from lxyu/word_cloud

add wordcloud chart
Update Vincent to 0.4.1
BUG: Use requirejs to pull D3 into the global namespace
REQ: Update version to 4.2
BUG: Ensure that if d3 is already loaded, requirejs doesn't try to load the module again
Adding import of initialize_notebok to __init__.
Improving IPython support.
Updating IPython example notebook.
More work to get vincent working on nbviewer.
Updating ipynb examples for nbviewer.
added a requirejs statement that checks for and loads topojson
Merge pull request #94 from AJRenold/load_topojson

Fix for 'TopoJSON library not loading in IPython notebook' in Issue #93
Merge pull request #97 from ellisonbg/html-display

Improve IPython support
REF: Cleanups for PEP8
add more marks, transforms, and properties

* some field references remain unhandled
add more transform properties