NavigationBar : Customization only for height

Includes:

- Allows user to customize navigation bar.
  Features :
   - Choose from 1-6 # of buttons
   - Re-arrange / assign buttons
  Id: Idc9f5f401f15d207504e49de47666bb5510a06ca

- Navbar : Rework logic for determining orientation
  This patch introduces better checks for hybrid ui's.
  This should fix issues of small buttons due to incorrect ui determination
  Thanks Rolf Arne Schulze for testing :)
  Id: If5b61dc4764a98deedb5b801d11451fed2488cba

- Fix layout on N10
- Remove uncessary padding and logic
- Phone fixes
- Phone padding fixes

Change-Id: I8903b85b6ee8581f8564d9dc7b0d40f645d7647a

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/res/values/strings.xml
NavigationBar: Custom height (1/2) - pbeeler credits