Test loading voxel-engine via voxel-cs
Load materials if isClient instead of game.isClient
Revert for now "Test loading voxel-engine via voxel-cs"

Requires many more changes to client/server plugin loading/API

This reverts commit d6402135e0991908f83c57b060e373c917f08b72.

Ref GH-26
Add voxel-zen, press F1 to hide/show UI clutter