Core/Movement: Implement spline movement subsystem.

Spline movement controls movements of server-side controlled units (monster movement, taxi movement, etc).
Proper implementation of effects such as charge, jump, cyclic movement will rely on it.
However, need improve our states system before.

Technical changes:

* Added linear, catmullrom and bezier3 splines which based on client's algorthims. They can be reused for proper transport position interpolation.
* Precission increased. There are no more position desync issues since client's position calculation formulas used.
* Now possible to move by paths with multiple points, send whole path to client.

--
Original author of research and implementation: SilverIce. Massive kudos.
Original port for Trinity (ref #4629) Chaplain and Venugh
With the following incremental fixes during my review:

- Restore flightmaster end grid pre-loading
- Fix uninitialized Creature::m_path_id
- Add missing trinity_string entries for .movegens command
- Fix a bug in WaypointMovementGenerator that would trigger unexpected pausing at waypoints for various amounts of time

Known issues:
- Errors like WaypointMovementGenerator::LoadPath creature XXX (Entry: YYYYY GUID: ZZZZZZ) doesn't have waypoint path id: 0.
This is caused by bad DB data. This commit didn't "break" it.

Do not forget to re-run CMake before compiling.

src/server/game/Movement/MotionMaster.h

@@ -39,7 +39,7 @@ enum MovementGeneratorType
     MAX_DB_MOTION_TYPE    = 3,                              // *** this and below motion types can't be set in DB.
     ANIMAL_RANDOM_MOTION_TYPE = MAX_DB_MOTION_TYPE,         // AnimalRandomMovementGenerator.h
     CONFUSED_MOTION_TYPE  = 4,                              // ConfusedMovementGenerator.h
-    TARGETED_MOTION_TYPE  = 5,                              // TargetedMovementGenerator.h
+    CHASE_MOTION_TYPE     = 5,                              // TargetedMovementGenerator.h
     HOME_MOTION_TYPE      = 6,                              // HomeMovementGenerator.h
     FLIGHT_MOTION_TYPE    = 7,                              // WaypointMovementGenerator.h
     POINT_MOTION_TYPE     = 8,                              // PointMovementGenerator.h
@@ -48,8 +48,10 @@ enum MovementGeneratorType
     ASSISTANCE_MOTION_TYPE= 11,                             // PointMovementGenerator.h (first part of flee for assistance)
     ASSISTANCE_DISTRACT_MOTION_TYPE = 12,                   // IdleMovementGenerator.h (second part of flee for assistance)
     TIMED_FLEEING_MOTION_TYPE = 13,                         // FleeingMovementGenerator.h (alt.second part of flee for assistance)
-    ROTATE_MOTION_TYPE    = 14,
-    NULL_MOTION_TYPE      = 15,
+    FOLLOW_MOTION_TYPE    = 14,
+    ROTATE_MOTION_TYPE    = 15,
+    EFFECT_MOTION_TYPE    = 16,
+    NULL_MOTION_TYPE      = 17,
 };
 
 enum MovementSlot
@@ -86,7 +88,6 @@ class MotionMaster //: private std::stack<MovementGenerator *>
         typedef std::vector<_Ty> ExpireList;
         int i_top;
 
-        bool empty() const { return (i_top < 0); }
         void pop() { Impl[i_top] = NULL; --i_top; }
         void push(_Ty _Val) { ++i_top; Impl[i_top] = _Val; }
 
@@ -107,6 +108,7 @@ class MotionMaster //: private std::stack<MovementGenerator *>
         void Initialize();
         void InitDefault();
 
+        bool empty() const { return (i_top < 0); }
         int size() const { return i_top + 1; }
         _Ty top() const { return Impl[i_top]; }
         _Ty GetMotionSlot(int slot) const { return Impl[slot]; }
@@ -158,10 +160,11 @@ class MotionMaster //: private std::stack<MovementGenerator *>
         void MoveTakeoff(uint32 id, Position const& pos, float speed);
 
         void MoveCharge(float x, float y, float z, float speed = SPEED_CHARGE, uint32 id = EVENT_CHARGE);
-        void MoveFall(float z, uint32 id = 0);
         void MoveKnockbackFrom(float srcX, float srcY, float speedXY, float speedZ);
         void MoveJumpTo(float angle, float speedXY, float speedZ);
-        void MoveJump(float x, float y, float z, float speedXY, float speedZ);
+        void MoveJump(float x, float y, float z, float speedXY, float speedZ, uint32 id = 0);
+        void MoveFall();
+
         void MoveSeekAssistance(float x, float y, float z);
         void MoveSeekAssistanceDistract(uint32 timer);
         void MoveTaxiFlight(uint32 path, uint32 pathnode);