Performance update and usability update!

A Performance and usability update!
- Made trails cache when not in use, this should stop performance to degrade over long playtimes.
- Fixed a bug that spawned invisible items, that could have worsened performance a lot for long playtimes.
- Simplified physics for log dropping trees and items, so no potentially crazy behavior now.

- Added a gamepad controls help (hold gamepad special left to view)
- Fixed the "unstick player" tool, and moved it to a "HELP" menu with other useful commands to ease playing the game at this stage.

- Added user adjustment option to camera movement speeds. (in Options > Game)
- Disabled dev-menu by default (it can still be turned on in options.)