Adam Barth 4fb47600e4 Add a Velocity class to be explicit about units
We were using an Offset, which represented pixels/second, but it wasn't
clear to clients whether that was pixels/ms. Now we use a Velocity class
that is explict about the units.

Fixes #1510
Fixes #785
2016-02-13 22:59:09 -08:00
..
2016-01-20 15:58:05 -08:00
2016-02-11 00:06:23 -08:00