SystemUI: Fix notification header disappearing on tablets

For some reason, the notification panel header has weird dimensions
when it has anything else than its original ColorDrawable as
background, and only on tablets.

We workaround this by not changing the drawable until requested.

Change-Id: Id76a5dcacf59c35b2e49681d6eeb4e828f7cbc58
SystemUI: Cleanup and enhance notification drawer header

- Crop properly images on tablets and landscale
- Use a separate layer instead of breaking header background
- Fix bug where you couldn't turn header back on after turning it off
- Added a gradient overlay

Change-Id: Ife399b82a3f272fb2ecc8e738c5f274f7682a556

Conflicts:
	packages/SystemUI/res/layout/status_bar_expanded_header.xml
SystemUI: UX: Make non-flip tiles slightly flippable

I always end up with people trying to flip non-flip tiles, and thus
it just acts like a long press on that tile. To give a better feedback
on tiles that aren't flippables, we let the tile slightly flip when
dragged, then get back into place when the finger goes up.

Change-Id: I14fddfc2033320bf447aab0bc6a1a49f77d8555e
SystemUI: Make QS tile reset more user friendly

By not closing the QS and allowing further editing

Change-Id: Ia8ebeeed7b72aa8d017a892c5978ffad3a4f8ac8
base: fixed missing shading of statusbar circle battery and network traffic

http://jira.omnirom.org/browse/OMNI-326

PS4:
handle traffic like signal cluster

Change-Id: I10c0f0fd1d63e78c9a1d09d1bff6a5221b8adec5
Base: add Sleep Mode Flip Tile

Sleep Tile Flip into SleepMode Tile

Change-Id: I84b6e7125f4cc4eca58e576441442e94e5553dca