Close notification panel when swiping away the last clearable
notification.

Change-Id: I4e5114f66e799a7c80e18b38abce5678da460846
HALO: fix the integer division bug

The newHeight is calculated by an integer division, which leads to an
ugly bug. E.g. a 95x96 image will get a newHeight of 0 because
(95 / 96 * 113) equals to 0. This will lead to a SystemUI FC.

Fix it by multipling first and dividing afterwards.
HALO: batch message icon for hdpi and mdpi

It's hard to keep up with Paul hehe
Merge remote-tracking branch 'rootbox/jb-mr1' into HEAD