For https://github.com/MozillaReality/Spoke/issues/302

This reverts commit 17fbb3d5.

Only use the amount of memory needed in sharedbuffergeometry based on networked-drawing configuration. Only create a sharedbuffergeometry object when a pen is first spawned.
Also, reduce the amount of memory used by primitive entities (cursor, spawned pens, teleport-controls)

allow changing color and scale via mouse when holding alt or shift keys; fixing/changing input for rift.