If any shift state variants of alphabet keyboard layout is not
specified in KeyboardSet.Element, it will be automatically generated
from base alphabet keyboard definition.
This change also
* Eliminates KeyboardShiftState object from Keyboard.
* Removes various set shift state methods from Keyboard.
* Removes KeyboardSet.Element.elementAutoGenerate attribute.
* Separates "sticky" Key.backgroundType to "stickyOff" and "stickyOn"
* Add preserveCase flag to smiley, .com, and labeled special keys.
* Rename KeyboardShiftState class to AlphabetShiftState.
* Rename some attributes from *UppercaseLetter* to *ShiftedLetterHint*.
* Introduce shiftedLetterActivated to Key.keyLabelFlags
Change-Id: I01a0a8efeeaa76820ae728a5bdfa8d02b6ce74b7
