Performance issues

[jhird11]

I've spotted several performance issues that should be addressed.

The tutorial level import contains a preview camera. Which renders the whole scene even though its not attached to a viewport

The lidar is by far the most expensive bit of scripting we have. A review of how it is doing its drawing should take place to make sure its not being more expensive than necessary.

[jhird11]

@gabriellamiles Not sure what the preview camera is about.. perhaps generated by a tool you use to import the meshes?

[jhird11]

I deleted the camera in the mesh scenes

[jhird11]

I also changed how the lidar draws dots to the screen to use rectangle blitting rather than looping through pixels.

Also changed lidar to avoid doing as many overlay operations each frame

[mhl787156]

Removing old scenes also helps a lot! The smaller the file size the better the whole thing performs