Add LLMotionController* LLMotion::mMotionController

This is needed for synchronization: motions will have to start
(with a specific start time offset) from a point in the code where
only the motion object is available.

I added/used LLMotionController& in a previous commit, this was
now changed into a pointer. There is (obviously) not much reason
for that, but also no disadvantage: the diff relative to LLs code
doesn't get larger since the references where already added, too.

Conflicts:
	indra/llcharacter/llkeyframemotion.cpp
	indra/llcharacter/llkeyframemotion.h

indra/newview/llphysicsmotion.h

@@ -49,7 +49,7 @@ public:
 	std::string getString();
 
 	// Constructor
-	LLPhysicsMotionController(LLUUID const& id, LLMotionController& controller);
+	LLPhysicsMotionController(LLUUID const& id, LLMotionController* controller);
 
 	// Destructor
 	virtual ~LLPhysicsMotionController();
@@ -61,7 +61,7 @@ public:
 
 	// static constructor
 	// all subclasses must implement such a function and register it
-	static LLMotion* create(LLUUID const& id, LLMotionController& controller) { return new LLPhysicsMotionController(id, controller); }
+	static LLMotion* create(LLUUID const& id, LLMotionController* controller) { return new LLPhysicsMotionController(id, controller); }
 
 public:
 	//-------------------------------------------------------------------------