This change introduces:
* New KeyboardView attribute
* keyLargeLetterRatio to specify large letter text size.
* keyHintLabelRatio to specify hint label text size.
* keyHintLabelColor to specify hint label text color.
* keyPreviewTextRatio to specify key preview text size.
* New Key.keyLabelOption flags
* alignLeftOfCenter, align the key label slightly left of the key center.
* largeLetter, use keyLargeLetterRatio to draw key letter.
* hasHintLabel, draw keyHintLabel at the right of key letter.
* followKeyHintLabelRatio, draw the key label following keyHintLabelRatio size.
* Renames
* Key.keyHintLetter to keyHintLabel.
* Key.keylLabelOption fontFixedWidth to fontMonoSpace.
* Key.keylLabelOption popupHint to hasPopupHint.
* Removes
* number icon releted attributes and declarations.
Change-Id: I2f456737e3a46209e5f48b5155951b2b21a33859
