Squashed 'js/d3.axes/' changes from f855374..1538f3b

1538f3b add x label\

git-subtree-dir: js/d3.axes
git-subtree-split: 1538f3bef4ebb3029d96d3a925d899ca293e1c84
Merge commit 'd8535dfe52eb3f930a19d082bfb24a3c0e8f572f' into gh-pages
Squashed 'js/d3.axes/' changes from 1538f3b..b8c6f3a

b8c6f3a add y label\

git-subtree-dir: js/d3.axes
git-subtree-split: b8c6f3abc5312d05da72627c14c8202ef8b4e9be
Merge commit '3b04947bca15e122e1ad6a5289677562e52901fb' into gh-pages
Squashed 'js/d3.axes/' changes from b8c6f3a..254cc51

254cc51 distance of y label = 1 em

git-subtree-dir: js/d3.axes
git-subtree-split: 254cc5198197311256f974a5674bf89c81aa7af1
Merge commit '512d7c23ed7132f1608ea841325089f21ba30312' into gh-pages
add labels to axes
two plots on a line for md devices