Added group and mask properties to RigidBody component.

Group defines which collision group the body belongs to, each type has a default (DEFAULT, STATIC, KINEMATIC, TRIGGER; for dynamic, static, kinematic, triggers)
Mask defines with which other groups collisions occur. Each type has a default (ALL, NOT_STATIC_KINEMATIC, NOT_STATIC, NOT_STATIC; for dynamic, static, kinematic, triggers)

New properties available on rigidbody: entity.rigidbody.group, entity.rigidbody.mask

Also added `teleport()` method to RigidBodyComponent