N900: notify users without CSSU when they try to launch the QML GUI

[Martin Kolman]

As vanilla Fremantle PR 1.3 has an old Qt version that is limited to Qt Quick 1.0 support, running the QML GUI won't work - it will just crash due to missing elements (PinchArea? and others).

• the user should be shown a simple notification screen with an OK button
  • "Unfortunately, the modRana QML GUI needs CSSU to work. Either upgrade to CSSU or continue using the classic modRana GUI. For more info about CSSU: ​http://wiki.maemo.org/Community_SSU"
• either a small PyGTK application or a dialog launched from a shell script (if possible)