Create planet/geoid UI components at init, fixes unit change NPE [1551]

Guys - fixes this problem which exists in both IDV and McV:

1. Load any test image (e.g. RTIMAGES most recent GOES IR)
2. Display -> Add Range and Bearing
3. Note distance readout in km
4. Click "Range and Bearing" to bring up Control window
5. Edit -> Change Display Unit
6. Any choice fails with NPE 

Making sure the ref'd objects exist when init() is called resolves this.