Added Soft Keyboard Sample project under ime-scan folder.
Merge pull request #86 from jorgesilva/develop

Revert "Merge pull request #83 from ericwan78/issue-70"
Add preferences screen to a11y service.
Corrected a resource path.
Created classes for IME scanning.
Added key icon graphics resource file.
Added TeclaIME  to follow the inheritance of IME in tecla-framework.
Added method to gain access to an instance of TeclaIME.
Implemented IMEAdapter methods.
Create the basic structure of switches.
Created a single-switch touch interface.
Added click and long-click listener in single-switch interface.
Plugged single-switch interface into TeclaIME (interface only shows when keyboard shows).
Moved keyboard init to setKeyboardView method in IMEAdapter.
Plugged IMEAdapter into SoftKeyboard.
Unplug IMEAdapter before hiding keyboard.
Connected the single-switch touch interface to IME.
Renamed TeclaShieldSwitch to GenericSwitch.
Implemented automatic scanning.
Rewrote TeclaShieldSwitch1 as an inner class of TeclaShieldSwitchCollection.