Traffic Simulator

Notable additions/changes:
- Nodes, traffic lights and traffic light controllers are no longer destroyed by explosions.
- Changed detector zone to enclose all blocks that are clicked.
- Added support for stacking bulbs on traffic lights.
- Added min brightness option for traffic light bulbs (inside content packs).
- Added Item load and Item unload tasks for routes.
- Added junction program block.
- Added ability to add multiple texture to traffic lights.
- Added 3d traffic light list.

Notable fixes:
- Fixed canvas editor not accepting text field inputs.
- Fixed crash with typing letters in offset screen.
- Fixed bug where animations added thru packs could be edited.
- Fixed crash with previewing road paint lines that are too long.
- Fixed crash with looping routes.
- Reduced traffic lights flickering under certain circumstances.
- Fixed bug where successful actions on an item click would still allow the off-hand to interact.
- Fixed coordinate picker screen not generating background map image around player position.