Add ViewReplicator class.
Add ViewReplicator class.

Summary: This class is primarily used by transitions to create replica views.

Reviewers: O2 Material Motion, #material_motion, chuga, O4 Material Apple platform reviewers

Reviewed By: chuga, O4 Material Apple platform reviewers

Subscribers: chuga

Tags: #material_motion

Differential Revision: http://codereview.cc/D2612

material-motion/material-motion-swift,material-motion/material-motion-swift