Squashed 'subtree/bokehjs/' changes from 0bce808..6f15b52

6f15b52 made hemlib more general, so that it can handle multiple working dirs

git-subtree-dir: subtree/bokehjs
git-subtree-split: 6f15b5200f27f6cc45612582949ecbf62f532638
Merge commit '5ed633cfe2f26fbdcc199a2c902fe27147472eec' into hem
migrated to hem
made embedded html stuff work with new hem stuff
setup.py now downloads compiled js from github
added hem information to readme