fb: Handle navbar heights correct on dpi changes + more (1/2)

Till now we set the height in px in the settings. Which is a problem
especially on multiDPI roms like we are when the user afterwards changes
the dpi due that it isn't calculated correct anymore on the new dpi.

This commit does
- save the dp value in provider and calculate the real px in fb
- clean up the settings stuff for it + do it a bit nicer (only settings part
  where we do not set the value for the listview)
- as well this commit disables movable navbar for tablets (we may will enable
  it in future but it needs a lot more work to have it on tablets correct working)
- add Converter class for common methods we always use....till now only px->dp
  and dp->px method

Change-Id: Ib962b2cd62c991fe4d6f3b6b27b5d97c9ec653b0
Frameworks: Lockscreen Colors and Lock Image [1/2]

PS2: Separate all color elements
	into separate prefs.
	Also colorize bouncer frame
	for secure lockscreens.
PS3: Whitespace

PS?: Add Lock Icon Picker =]
PS?: Add "Colorize Custom Icon" option.

Change-Id: I542dfa01bb1d3d0e401bbf8a5f58b32f08cbfc62