Template can be used for several cases:
* Unique creature that are already spawned in database (requires creature.MovementType=2 like guid based creature_movement)
* Summoned creature that has a pre-defined path (requires creature_template.MovementType=2)
Note that creature_template.MovementType=2 should be used with care, and must not be used for creatures that may be summoned in random locations in world.
Added additional startup checks for existing creature_movement-table
Signed-off-by: NoFantasy <nofantasy@nf.no>
