[_fixed] Flow type for TweenPerformerWeb's PlanAndTargetT
[_fixed] Flow type for TweenPerformerWeb's PlanAndTargetT

Summary: There's [a bug in Flow](https://github.com/facebook/flow/issues/2074) that requires the most specific type in an intersection to come first.  Working around it here by changing the order of the intersection.

Reviewers: #mdm_core_contributors, markwei

Reviewed By: #mdm_core_contributors, markwei

Differential Revision: http://codereview.cc/D1203

material-motion/material-motion-js,material-motion/material-motion-js,material-motion/material-motion-js