reorder source files for grunt
implement bounding sphere for labels

This fixes rendering for labels. Also, add a transparent
background to the labels, to make them easier to read.
properly close start and end of tubes
use high precision in shaders

The medium precision shader was causing problems for rendering with
outline mode on the iPad. The whole structure would appear in black.
This fixes #62.
use zurb foundation for a better experience on mobile
Merge remote-tracking branch 'biasmv/master'

Conflicts:
	index.html