h3. Successful Startup sequence
- test applet is added to the page
- state: 'test applet appended'
- polls testApplet.areYouLoaded() to see wait for it to be ready
- real applet is added to the page _appendHTML( self.getHTML() )
- state: 'appended'
- polls appletInstance.getSensorRequest(this.measurementType)
- test applet is removed from the page
- state = 'applet ready'