[1/2] SystemUI: Add time-context headers to the notification header

This commit adds image headers to the notification panel header,
based on the date/time. There are pictures for morning, afternoon
and night, as well as special events like Christmas and new
year's eve.
More will be coming, with eventually a way to use an external
(as in, Internet) provider for those pictures.

Change-Id: Ie3321e9a3e0637d6ba8094dd46aee36c41354713

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
Re-do contextual notification header images

PS2: morning
PS3: night
PS4: new night image
PS5: new morning image
----------------------After Rescue-----------------
PS6/4: Shift morning image
PS7/5: New Years image
PS8/6: New morning image (Credits: Lokesh Chamane)
PS9/7: Revert back to old morning image
PS10/8: new Christmas image

*I cropped these for the different resolutions instead of scaling. Let me know what you think*

Change-Id: I1f713f12b425dd63a98ec85f185606e36411c308
Add evening time to header

Change-Id: I5d9a41d92803d64f67cf2fb9dd2c4294a947efc3
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

Conflicts:
	packages/SystemUI/res/layout/status_bar_expanded_header.xml

Change-Id: Ife399b82a3f272fb2ecc8e738c5f274f7682a556

Conflicts:
	packages/SystemUI/res/layout/status_bar_expanded_header.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
Tweak the time for Status Header

Change-Id: I9d4043dba48707b8e4f123fccce1dbb608d107dc
Signed-off-by: Lokesh Chamane <lokesh.c703@gmail.com>
dpi on the fly {1~2}
fix hdpi f/c after header cleanup