Added steering centre members to VehicleData.

steeringReturn is the main control for the amount of return in
the steering. Setting it to 0 (the default) disables steering return
completely.

steeringReturnSpeedScale is a multiplier on the amount of effect that
the vehicle's velocity has on its steering return.

powerSteering can be set to eliminate the effect of steering return on
user input. Without this flag set, the user will have a harder time
steering, because the wheels try to return as they steer. If this flag
is set, steering return will not be applied while the user is actually
steering, only when they release.
Added steering return to Vehicle.

It happens in Vehicle::updateMove so it can apply to all vehicle
subclasses. It is applied to both x and y steering.
Fixed stream read/write mismatch bug.

It was causing Vehicles to roll forwards with a constant velocity when
stationary, and ignore move->y.
Add getMaxDamage() method.  This will be needed for the forthcoming HealthTextHud GuiControl.
GuiHealthTextHud.  A C++ GuiControl that replaces the scripted numerical health hud.
Removed the scripted numerical health hud in the Full Template and added the new GuiHealthTextHud control to the playGui.
Script changes for the Full PhysX Template to remove the scripted numerical health hud, replacing it with the c++ GuiHealthTextHud GuiControl.
Send back RayInfo distance with ContainerRayCast

Added an 8th word to ContainerRayCast's return, which is the distance.
Doc changes for RayInfo distance

Doc changes for the containerRayCast DefineEngineFunction to include the
distance.
BitVector don't have copy-constructor/operator=
Added compilation information to README.md
Updated readme with PhysX 2.8.4.6 information.
For for Issue #106 Convex Shape Bandwidth
Merge pull request #107 from DavidWyand-GG/issue106-ConvexShapeBandwidth

For for Issue #106 Convex Shape Bandwidth
Fix for Issue #108 Turret Heading Node
Merge pull request #109 from DavidWyand-GG/issue108-TurretHeadingNode

Fix for Issue #108 Turret Heading Node
Fix for Issue #111 for BitStream Issues
Merge pull request #112 from DavidWyand-GG/issue111-BitStreamIssues

Fix for Issue #111 for BitStream Issues
Fix for Issue #110 for Particle Emitter Ejection
Merge pull request #113 from DavidWyand-GG/issue110-ParticleEmitterEjection

Fix for Issue #110 for Particle Emitter Ejection