Bug: 3216592
Change-Id: I88f8055199f2cd0525faf9374114fbebba53b951

With this change,
- Shift and Shift lock state of keyboard is maintained by
  LatinKeyboard.ShiftState.
- Shift key state is maintained by ShiftKeyState object in
  KeyboardSwitcher.
- LatinIME informs KeyboardSwitcher that shift key press, release and
  long press and KeyboardSwitcher determines which state LatinKeyboard
  and ShiftLeyState should be.

Bug: 3193390
Change-Id: I948ef26fda512eb1cb0ebddc89d322c4f4f4d670

This change partially implements the requested feature. The following
are not supported yet.
- Non-letter key handling on automatic temporary upper case layout.
- Non-letter key handling on shift chording in caps lock layout.
- Hint icons for manual temporary upper case layout are not final ones.

Bug: 3193390

Change-Id: I636da99d1be05b1337935d87c6f4d140661e1cc8

Change-Id: I0d92e513757e765d9de98561205754af5a143650

Because there may be very long key, such as space bar on tablet, we
should not use the distance between the touch point and the center of
key as proximity detection.  Instead of that, this change uses the
distance between the point and the nearest edge of key as proximity
detection.

Also this change fixes the bug that space key (code 32) was not
counted in proximity detection.

Bug: 3164020
Bug: 3168138
Change-Id: I687f1ce94a8e944c3f6eea0fe00e18ed6e68e278

Bug: 3122894

- Changed width 10 -> 32
- Changed height 5 -> 16

Change-Id: I07354cf5c942974cc25a5e043f41e0f13a09351b

Bug: 3082538
Change-Id: Ic0d72c6fe08cfc20db86aeffb10a27efe678095e

Bug: 3082538
Change-Id: If0ddf32bc3811e3c65a7a96503c61ed3351eeb66

Change-Id: I241125b5b15c9d6bbba456476f1f4fd3ef9db3f2

Bug: 3109804
Change-Id: I316f9cfcec377a7d0ea1417e1e3cea55cbdb9e2b

Change-Id: I4c5a37315dea1c7545b77a8a6c93b930927a5a82

Keyboard XML file can include other keyboard XML file using directive
<include keyboardLayout="@xml/...">.  The keyboard XML file which is
included must have <merge> tag as root element.

Change-Id: I06c35fe7b3db5232acdb33f73a79f38d31261b32

This keyHintIcon attribute is used to specify hint icon drawable at
top right corner of Key.

Change-Id: Icaa91e63c4473b2513396bd3fbeb8ed6fd73586c

Change-Id: Ie840ae113ee6bd5b629a90959d7f955a5ceba95a

Change-Id: I8b310c2c0cae1a151e53c22001c586697346982c