- removal of unusal imports
- unused MobileElementToJsonConverter was removed
- IOSMobileCommandHelper: methods that hide keyboard were moved to MobileCommand

 - constants which describe commands that supposed to be common for all the platforms  have package-visibility now.
  - The argument preparation for the lockDevice command was moved to the MobileCommand.

- JsonToMobileElementConverter is not rhe abstract class now. It generates instances of MobileElement subclasses according to current session parameters
- JsonToAndroidElementConverter is deprecated now
- JsonToIOSElementConverter is depreacated now
- JsonToYouiEngineElementConverter is deprecated now.
- MobileElement is the abstract class.
- the new automation type `youiengine` was added.
- more strict contract beetween AppiumDriver subclasses and MobileElement subclasses was provided:
   - AppiumDriver stays the  generic class
   - AndroidDriver now generates only AndroidElement
   - IOSDriver  now generates only IOSDriver

...and the additional test for AppiumDriver for Android

it is not correct because we automate tot only native apps. There are mobile browsers and hybrid apps.