Added support for radians in wrapAngle

My first time proposing a change in GitHub, so I hope I did it correctly.
Merge pull request #597 from Cryszon/patch-1

Added support for radians in wrapAngle
Added basic Webcam plugin.
Added Device.getUserMedia detection.
Updated config.php so you can toggle physics engines on/off via flags.
Updated Gruntfile.js so it builds a Phaser + Pixi but no Physics libs.
Fixed the Loader.preloadSprite crop effect on WebGL.
Math.removeRandom allows you to remove (and return) a random object from an array.
Updated TypeScript defs to fix getRandom (fix #583)
Fixed Grunt script that stopped the P2 constraint classes from building properly.
World.destroy incorrectly clashed with the Group.destroy method it over-rode, renamed to World.shutdown and updated StateManager accordingly.
World.shutdown now removes all children iteratively, calling destroy on each one, ultimately performing a soft reset of the World.
Objects with a scale.x or y of 0 are no longer considered valid for input (fix #602)
InputHandler will set the browser pointer back to default if destroyed while over (fix #602)
Group.destroy has a new parameter: `soft`. A soft destruction won't remove the Group from its parent or null game references. Default is `false`.
InputHandler.validForInput is a new method that checks if the handler and its owner should be considered for Pointer input handling or not.
Group.replace will now return the old child, the one that was replaced in the Group.
Build update for testing.
ArcadePhysics.separate doesn't pass over to seperateX/Y if overlapOnly is true (fix #604)
ArcadePhysics.collideSpriteVsSprite checks if both objects have bodies before processing.
ArcadePhysics.separate doesn't pass over to seperateX/Y if overlapOnly is true (fix #604)
ArcadePhysics.collideSpriteVsSprite checks if both objects have bodies before processing.
ArcadePhysics.Body now checks the ArcadePhysics.World bounds, not the game bounds.
ArcadePhysics.Body has reverted to the 1.1.3 method of preUpdate, so you can now position sprites with x/y, drag them, etc, regardless of the Body.moves flag (issue #606)
ArcadePhysics.World now has setBounds and setBoundsToWorld methods, which are called automatically on world resizing.
ArcadePhysics.Body no longer sets the offset to match the anchor.
Debug.spriteBounds will now take the position of the camera into consideration when rendering the bounds (fix #603)
Fixed SpriteBounds camera placement in Debug (again).
Removed un-needed cache vars from ArcadePhysics.World.
Tidied up ArcadePhysics.Body and fixed rotation parameters.
Every single Arcade Physics Example now runs perfectly under this release.
ArcadePhysics.World now has a checkCollision object which can be used to toggle collision against the 4 walls of its bounds.
Sprite.events.onEnterBounds added. This is dispatched if the Sprite leaves the bounds but then returns. The opposite of onOutOfBounds.
InputHandler.dragFromCenter will now work regardless of the anchor point of the Sprite.