Level Editor
- Changed the start, editor start and finish locations to centre left of entire map.
- Most of the state of the editor will not reset to default upon entering the editor.
- Added shortcuts information in the level editor which can be shown and hidden with the key 'H'. The information is only available for tiles, objects and start/end modes at the moment but most modes follow a similar shortcut theme.

UI and memory optimisation update (1st pass)
- The title, map and game screens have had many memory allocation issues removed which should help with the stuttering problems. For the curious, you can show GC memory usage via the video menu.
- Many texts have been optimised to pre-allocate memory instead of using concatenation which generates waste memory requiring stutter producing clean ups.
- UI windows are no longer updated and their render targets are no longer drawn when the UI is not visible. This only affects the map and title screens as the game screen already does this
- UI elements no longer render when not within the windows view greatly helping windows that contain a lot of text heavy elements such as the achievements window.
- Particles and trails have been optimised a bit but more work needs to be done here.
- Removed all function calls in Sprite, Particle and Tile render code to squeeze out some performance.
- Whenever a new screen or level is transitioned to the game time will reset to zero and the next update frame is skipped which forces the game to not catch up any time lost during loading. This used to happen between the game and the map screens but is now more aggressively used to eliminate loading time interference with the timer statistics.

- Leaderboards have been spruced up a bit with colours and proper rank texts. The Steam rank above your level time has also been spruced up to match.

I'm aware there could be still an issue with heavy stutters occurring at the start of the title, map and game screens. This is due to a large amount of particles and/or trail particles being allocated quickly I believe. I haven't looked too deeply into this yet but the above particle and trail optimisations will help a bit for now.