Mousing down paints without needing to 'scrub'

Previously the mouse drag event handler called the paint function,
which meant that you had to scrub the mouse around while also pressing
down to cause any painting.
Merge branch 'master-traffictype'
Merge branch 'master' into deploy
(Fixed) Mouse coords not updated on tapping (iOS)
Merge branch 'master-traffictype'
Merge branch 'master' into deploy