prevents voxel data from being sent or received (read: requested) when voxel rendering is disabled
also adds a menu option under "Tools" to enable/disable the Oscilloscope
bandwidth meter - avoid division by zero
Merge branch 'master' of git://github.com/worklist/hifi into 19376

Conflicts:
	interface/src/Application.cpp
upstream merge
changes broadcast function in Application to use a different name but the same signature as in NodeList
Merge pull request #626 from tschw/19376

Code Review for Job #19376