disabling auto-pick if backspace is pressed after an auto correction pick. Issue #366

Change-Id: Ic0b418edacc336955a619b49f55a1a043158a26f
fixing issue #371, refactored ModifierKeyState

Change-Id: Iad3469b0d86ebd17b027e51c2ff32006b87f003e
A small fix to complete #371. Resetting keyboard on setting it

Change-Id: Iea1d445fd0781c6ac5a330d7f68fd2a7199b8054