Add neuronviewer function
Change documentation from nat.as::getBoundinBox to boundingbox
Change neuronviewer() to nopen3d()
Merge branch 'feature/neuronviewer' of github.com:ajdm/nat into ajdm-feature/neuronviewer

* 'feature/neuronviewer' of github.com:ajdm/nat:
  Change neuronviewer() to nopen3d()
  Add neuronviewer function

Conflicts:
	R/neuron-plot.R (code added to bottom of file in both branches)
Merge branch 'ajdm-feature/neuronviewer'

* ajdm-feature/neuronviewer:
  Change neuronviewer() to nopen3d()
  Add neuronviewer function