Distorted Android

Avoid a crash on exiting MessageSender

fix in vertex shader

Bugfix in vertex shader (vertices were shot into outer space if P==S, i.e. if center point was exactly equal to the vertex being computed)

Progress with Vertex3D

Minor: deal with IntelliJ warnings

minor

Important bugfix in the vertex shader: there was division by 0 in case Center point was on the edge of the Object, resulting in some vertices being shot into outer space.

Vertex3D almost finished - there's still a problem when parts of Cubes get culled if the Object gets Deformed or Distorted to the left (curiously only the 'left' direction seems to trigger this!)

Cleanup, consistent variable names, minor details.

Further progress with SenderThread: make it possible to actually exit the thread on app exit.