File renaming. Starting on safe output type.

A la Anim<T> from timeline.
Moving validity checks into MotionBase.
Builds and runs with bare pointers.

Output variable type not yet in use.
Xcode auto-project-update.
Remove unused variable.
Finish logic stored in MotionBase.
Refactoring Motion.
Tween on mouse click.
Documenting functions.
Support for queueing motions.

Append motions to a Motion's Sequence.
Creating constructors for Motion types.

Heya, how about that?
Connecting to safer output types as well as bare pointers.
Motions constructed with output and sequence.

No more friendship needed with Timeline.
Motion creation methods for Output<T>
Properly disconnecting motions.
No more Timeline friend for MotionBase.
Queue methods working again.
Working on proper copy construction of Outputs.
R-value copying of Output<T> working well.