Bug: Losing render-commands if commandbuffer is full(gfx)

Problem:
If there is a new draw call, it is checked if there is enough free memory for the vertices in the databuffer but not if we have enough free space in the commandbuffer to add the command
So we lose some commands during a frame cuz the commandbuffer is full

This fixes the 2nd part of issue 1004
fixed last commit
set default value for asynchronous rendering to disabled for now. #1001