Changed contextual notification panel headers

See images - http://i.imgur.com/PupEJ5p.jpg

Change-Id: If848d162523610946c317919d2f6664d891906e6

Conflicts:
	packages/SystemUI/res/drawable-hdpi/notifhead_afternoon.jpg
	packages/SystemUI/res/drawable-hdpi/notifhead_christmas.jpg
	packages/SystemUI/res/drawable-hdpi/notifhead_morning.jpg
	packages/SystemUI/res/drawable-hdpi/notifhead_newyearseve.jpg
	packages/SystemUI/res/drawable-hdpi/notifhead_night.jpg
	packages/SystemUI/res/drawable-xhdpi/notifhead_afternoon.jpg
	packages/SystemUI/res/drawable-xhdpi/notifhead_christmas.jpg
	packages/SystemUI/res/drawable-xhdpi/notifhead_morning.jpg
	packages/SystemUI/res/drawable-xhdpi/notifhead_newyearseve.jpg
	packages/SystemUI/res/drawable-xhdpi/notifhead_night.jpg
	packages/SystemUI/res/drawable-xxhdpi/notifhead_afternoon.jpg
	packages/SystemUI/res/drawable-xxhdpi/notifhead_christmas.jpg
	packages/SystemUI/res/drawable-xxhdpi/notifhead_morning.jpg
	packages/SystemUI/res/drawable-xxhdpi/notifhead_newyearseve.jpg
	packages/SystemUI/res/drawable-xxhdpi/notifhead_night.jpg