Added visualization of obstacles. Fixed relative font path issue in 3D widgets by using QFont within osgText::Font instead of using static font filename.

Substantially bugfixed and improved deactivation/activation and persistence of widgets. A lot of testing of Google Earth view, only minor improvements

Fixed initial startup bugs, cleaned up the activation-deactivation of update timers. Added initial instructions for new users.

Added command to select target position for robot - command can be accessed via a right-click in the 3D View perspective --Lionel