No collisions with launcher

Resolves #57
Remove unnecessary copy constructor from WritableVirtualController.
Introduce the new input functionality. Some old buttons are now obsolete.
Migrate all controller clients to use the new buttons.
Add comments for the new virtual buttons.
Modify key mappings to fit the new input spec.
Split the Simulation into 2 classes.

Had to add a new gameplay constructor and modify the simulation one.
fixed the game killing bug of restarting the editor.
Fix the ordering of Draw() calls.

The ball was being drawn underneath the launcher, and the "hand" of
the launcher is now drawn underneath the launcher's base.
Merge remote-tracking branch 'origin/master' into brian-editor

Conflicts:
	PuzzlePathDimension/Menus/GameEditorScreen.cs
	PuzzlePathDimension/Menus/PauseMenuScreen.cs
	PuzzlePathDimension/Menus/ToolboxScreen.cs
Make the game background less saturated.
Remove white pixels from the platform textures.
Tweak the platform textures.

Edges have been added to the ends of each platform, and the diagonal
lines in the texture have been made more smooth.
Change the pixels on the edges of the launcher's base.

It only looked good if the background was white, but it isn't.
Change the pixels on the edge of the death trap's texture.
Change the pixels on the edge of the ball's texture.
Change the menu background.
Fix issue #96.
Read par times and calculate the score.

I haven't added par times to the XML files yet, though. Also, there's
no way for another class to know the score yet. I'll do that later.
Code clean up

fixed typo and renamed simulation to editableLevel in GameeditorScreen
Limit toolbar

prevents toolbar from displaying a certain type of platform or
orientation or both.