The code to create the interactive guideline is now placed after
the code that creates the legend.
This fixes an issue where the guideline would extend past
the X-axis, when the legend was more than two lines.
Merge branch 'development' of https://github.com/novus/nvd3 into development

Conflicts:
	nv.d3.min.js
Fixing issue where the 'IndexLine' in cumulative line chart was not draggable.
Needed to move interactive layer to the bottom of the SVG layer stack, and change pointer-events to none
for things above it.
Rebuilding nv.d3.js