Revert "Hopefully fix crash when using SHM buffers - we should release them too. WIP"

This reverts commit 5641cb621a63bc0361850324977247e700cf53d4.
Revert "Resolve flickering issue when texture is disowned before scenegraph has a chance to update"

This reverts commit 73e40e08a1cff46be2ef7deea1b7f130332eee00.
Don't disown() buffer until a new texture id is requested