fb: add back all keyboard IME features back (1/2)

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: I71e93c39620cc171e658b2d7e26491bac97c651d
Merge branch 'lp5.0' of https://github.com/SlimRoms/frameworks_base into lp5.0-caf

Change-Id: I5f757c0d39484200a185018b947ccc75e6c23b59