[changed] Tossable to only use draggedLocation$ when spring is disabled
[changed] Tossable to only use draggedLocation$ when spring is disabled

Summary: This enables authors to take control of whether `draggable` or `spring` is in control.  For instance, in `Swipeable`, we want the spring to override the drag for part of the interaction.

Reviewers: O2 Material Motion, O3 Material JavaScript platform reviewers, #material_motion, featherless

Reviewed By: O2 Material Motion, #material_motion, featherless

Tags: #material_motion

Differential Revision: http://codereview.cc/D3329

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