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)

This reverts commit 7c7978be.

fix issue where scroll-scaling wasn't updating its local scale value; fix issue where media-loader wasn't setting the bounding box corrrectly in certain cases

reduce how often sharedBuffer.update() is called to improve performance, especially when first loading into a room that has existing drawings.

fix bug that occur because clients were assuming mutual dataChannel connections when that is not always true (client B can't assume it can message client A even if it has received a message from client A already)

Android as a standalone HMD