ATMS - More UI work

I'm continuing on and will probably have a more interesting game by Wednesday, hopefully with multiplayer. This afternoon was lots of UI work to improve controls and instructions.

Done:

- Title/menu screen tuning
- Remapped keyboard keys: ASD left stick, +- right stick, arrows are D-pad, and ESC is START
- View controls
- Pause menu
  - Resume
  - Restart mission
  - Abort mission
- Menu drop shadows
- Move programmable pipeline drawRect2D to G3D
- Move signedPow to G3D
- Add G3D::Scene::remove and override in World to support object destruction
- Allow choice of gates in tutorial
- Tutorial popup text boxes on gates

Next:

- Finish sailing tutorial

- Point wind arrow INTO boat (thanks, Chris)

- Targets (anchored ships, shore targets)

- Cannons!

- Abstract everything about the player, to enable splitscreen multiplayer

  - e.g., player1Ship

  - add a Player object that the ship references

  - make tint/materialpose a property of the player