Changing template/qmljsdbg-lib as suggested in QTCREATORBUG-2885

- Renaming the screen orientation enum and keys
- Explicit constructors
- Virtual destructors
- Renamed some occurences of 'Qml' in comments to 'QML'
- Adding descriptive comments to all generated files which should
  not be touched by the user.
- Adding missing license headers to the qmljsdebugger sources

Task-Number: QTCREATORBUG-2885
Reviewed-by: Friedemann Kleint
Reviewed-by: dt