[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
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
StatusHeader: night begins two hours earlier, at least its dark outside

Change-Id: Ic044b26f7820828c11c5a3baa2ad22269c8dac02

Conflicts:
	packages/SystemUI/src/com/android/systemui/omni/StatusHeaderMachine.java
Fix updating of the status bar header image