Finish previously incomplete pull request #263
Fix scatter single point class removal

Once a scatter is rendered with a single point, it would keep this
setting even on the updates where more points might have appeared. Redo
the single point detection each time and set the class accordingly.
Fix voronoi errors on scatter chart
Bugfix: Cumulative Line Chart. Indexify needs to use original lines.y() function.
Moved variable closer to function where it is used.
Merge pull request #478 from novus/bugfix/cumulative-line-bug

Bugfix: Cumulative Line Chart. Indexify needs to use original lines.y() function
Merge remote-tracking branch 'remotes/novus-original/development'
Fix typo in README
Merge remote-tracking branch 'remotes/Marsup/fork'

Conflicts:
	nv.d3.js
	nv.d3.min.js
	src/models/scatter.js