Alternative look for sun (code not tidied yet)
Reorganise sun drawing to have proper opaque and translucent passes
Experimental: sun glare layer
Adjust parameters slightly, fix atmospheric fog on translucent pass
Fix potential overheating bug when leaving planet for sun
Mac build niggle
Remove some unused member variables
Nova and related adjustments

- increase default corona flare
- increase nova corona flare ranges to match
- make nova stars in expansion phase keep high corona flare
- make flare changes in nova mission use frame callback for smooth changes
Depth-buffer bug fixed
Merge pull request #42 from OoliteProject/new-sun

Pull request for new sun accepted to master.