Answer call with hardware HOME button (2/2)

preparation to winter time

Change-Id: Ic11449acf87c6b4d932142b74158af7441658b3d

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

(cherry picked from commit b1ffd88a7e168851638fd080242fa509f58260ce)
Frameworks: Actually start to use HEADS_UP_REQUESTED extra

Prepairing slim heads up feature, we do this here to allow apps to
send a heads up notification no matter what.

Google introduced this flag but is not using it in the actual API

Take HEADS_UP_REQUESTED into account to indicate that this notification
is a good heads up candidate.

How to use it you can see in email or mms app

Change-Id: I4a29404122ae12ab9b95e1d223911078a360b44e
(cherry picked from commit a87eb27911e3edb20c7894db161113c8dba37f99)
SystemUI: Status bar clock - fixes

This commit fixes:

- no overlapping more from status bar icons on center clock.
  The width depending on what the user has setuped (date and clock) is exactly meassured now
- do not start animations if they are not needed
- reduce settings provider calls
- a bit cleanup

Change-Id: I7a37a6ae8f9bad0f265119af05dc20cf21cd6890
(cherry picked from commit 150d98c330a86e8f7976f37cc0b23d42a9a739bc)