SystemUI: fix memory leaks

ContentObservers are being registered without being unregistered,
causing old objects not to be garbage collected. This causes memory
leak if the classes are destroyed and recreated throughout the
device's uptime.

SearchPanelView is recreated every time the screen is turned on.
StatusBarIconView is created every time a notification is triggered.

JIRA: CYAN-650
Change-Id: Iabd3221fc2b0c848396af1790fd09424be602e7e

Conflicts:
	packages/SystemUI/src/com/android/systemui/SearchPanelView.java
	packages/SystemUI/src/com/android/systemui/statusbar/StatusBarIconView.java
Correct executable bit for source files

Many media files and source code files were marked as executable in Git.
Remove those.

Also a shell script and python script were not marked as executable.

Change-Id: Ieb51bafb46c895a21d2e83696f5a901ba752b2c5
Signed-off-by: Chirayu Desai <cdesai@cyanogenmod.org>