Cleaning up code for the MSIE svg.getScreenCTM issue.
REbuilding nv.d3.js
Adding unique ID to each tooltip in nv.models.tooltip.
Removing some code I added in tooltip.js that clamped the svg bound top. Wasn't actually working.
Adding IE9+ fix so that mousing over a tooltip does not trigger
the elementMouseout dispatch. Without this, tooltips on IE are very buggy.
Rebuilding nv.d3.js
Fixing bug on cumulative line chart where point hover circles
were not disappearing after moving the index line.
This is due to commit 065c8eb84d.