settings: add back all keyboard IME features back (2/2)
this commit adds:

- ime switcher notification - thanks cm
- slims fullscreen disable on landscape
- slims force autorotation on IME
- volume button control for navigate in the message - thanks cm
- slims force to show always enter key

some fixes to the 4.2/4.3 implementations + added full multiuser
support for all this features

cheers

Change-Id: I58596f11ee09c6db77119f3e3044e1ec2dd30c0a
cherry-picked from SlimRoms dfea82c32a5a32e8f26d081b9662b76ed34ce3a8y
Signed-off-by: Kristofer Ard <kristoferard@gmail.com>