SiO2 version 1.5.0
A quick patch to 1.4.0 that includes some additional features of the MovementState/MovementTarget code added in 1.4.0 that missed my commits.
Changelog:
- Added an initialize and terminate methods to MovementTarget for the MovementState to call when the target is set.
- Added an AbstractMovementTarget class to shield subclasses from future interface changes.