- removed FormSwitched from FormBase and added to DeviceSession (more logical message loop)
- added PreviousForm to DeviceSession, contains last opened form (at initial form is null)
-BotBase message loop update
- now navigation is possible from every form, not just the latest ones as before
- adding RequestUserLocation and RequestUserContact to Device class
- Update to Device class
- updating examples
- adding example for data upload
- small documentary Updates (Readme.md)