Input event changes

- New InputEventManager class.  It will be used by 3rd party input
devices to generate Torque 3D input events.
- Expanded the input event signal to include three new floats and a new
integer.
- Expanded the number of joystick buttons to 48.
- The input virtual map is now extendable rather than hard coded.
- The input devices types are now extendable rather than hard coded.
- New SI_POS, SI_ROT, SI_INT, and SI_FLOAT input event types.
- New SI_VALUE input action type.
- ActionMap has been updated to work with these changes.
- Removed unnecessary references to platform/event.h

Engine/source/app/mainLoop.cpp

@@ -291,6 +291,9 @@ void StandardMainLoop::init()
    tm = new TimeManager;
    tm->timeEvent.notify(&::processTimeEvent);
    
+   // Start up the Input Event Manager
+   INPUTMGR->start();
+
    Sampler::init();
 
    // Hook in for UDP notification
@@ -307,6 +310,9 @@ void StandardMainLoop::init()
 
 void StandardMainLoop::shutdown()
 {
+   // Stop the Input Event Manager
+   INPUTMGR->stop();
+
    delete tm;
    preShutdown();