Updates function documentation.
Adds kind for Assessment Item Tags.
Updates README.md.
Adds keyword session argument to class_converter functions.
Updates khanload. Uses nodecache in coach reports.
Merge commit '5b0c28506f700da2c6d7fd2fb7a25952936430dc' into hackathon
Adds instructions for updating KA-API-PY library.
Fixes reference to self in function definition.
Removes unused imports. Cleans up topic tree utils.
Merge commit 'bd00ceb4ad5362545a412fb44ce34224c7bce0b7' into hackathon
Adds hipchat notification to travis.
Makes khanload robust to dodgy data from KA. Updates data files.
Makes topic_tools robust to duplicate KA data.
Updates Exercise data API endpoint with new position data.
Cleans up Playlist/Sidebar integration. Adds topic icons.