Added support for multiple navigation key bars

System UI was build with the assumption that there is only one
navigation bar at a time, and that this bar is managed by
Phone UI, Tablet UI or TV UI.

This commit adds simple call back facilities at BaseStatusBar
for both, navigation key hints and menu key visibility change
events. These call backs are wired up in Phone UI, Tablet UI
and the TV UI stub.

This allows us to have more than on navigation key bar
in the UI and define those navigation bars directly
in BaseStatusBar, where it is available for all UIs.

Patch Set 2:
* CyanogenMod Code Style
* Added documentation.
* One interface for all
* Added setDisabledFlags() to the list

Change-Id: Id4de440e21c2f5c78b5e185030f9c5e0f7e6bef7
Bringing basic pie controls to CyanogenMod. (1/2)

Based on the multiple navigation key bar patch, this commit adds
basic pie controls to CyanogenMod. The implementation is inspired
by Paranoid Android but is completely rewritten.
The aim was to get as little intersection with existing code as
possible and provide a farily easy interface to extent these
controls by new slices (inherited from PieSlice).

The pie controls are only active when expanded screen is turned on.

Based on this commit there is another one that adds more optimizations
for Phone UI to pie controls. And there is a seperate commit for
the settings app, too.

Patch Set 2:
* Cyanogen Code Style.
* Some simplifications in PieSysInfo.java

Patch Set 3:
* Fixed NPE when pie controls are completely deactivated
* Preserve state of menu button

Patch Set 4:
* Fix display of Wifi SSID
* Some cleanup and coding style changes

Patch Set 5:
* Fix NPE when not connected to Wifi
* Remove AM/PM from time display (overlayed the other info)
* Fix menu button handling

Patch Set 6:
* Remove trailing whitespace in 12 hour time format

Patch Set 7:
* Tune colors
* Improve battery level and operator printout
* Remove some unused imports

Patch Set 8:
* Some refactoring on pie trigger management
* Copyright fix
* Make debug on PieLayout less noisy

Patch Set 9:
* Fix NPE one devices with no GSM/CDMA/LTE
* New color proposal
* Haptic feedback now respects system setting

Patch Set 10:
* Factor out haptic feedback into separate method

Patch Set 11:
* Prepare for "always on"
* David's color scheme

Change-Id: I90de7252d8301282d396c29bc9e9943acf7f2766