Generate path to Scene2Model installation in addS2MScheme.reg

Currently the path to the Scene2Model installation in the module/addS2MScheme.reg is hard-coded. Since the extension is installed through AdoScript and addS2MScheme.reg is located in some temporary file / folder during the installation the contents of addS2MScheme.reg could be generated (or modified) to use the installation directory of the tool. The "Application" GET_PATH command can be used in AdoScript to get the absolute path to the installation directory of the tool where it is executed.