Unified map & camera views

[BruceJohnJennerLawso]

Unlike KSP and Orbiter, the advantage of Ignition being in 2d is that a separate map view may not be entirely necessary, vessels could be rendered normally until the zoom is so far out that the flag indicator is visible. This would require some fading of different graphical elements (planet image fading out as we zoom in to see the terrain) but it would look really cool and be a bit easier to use. Map view rendering stuff like orbit traces could be done as a separate render bit that is transparent at high zoom, visible far out.

Tricky to implement, but could potentially be a really nice feature for the project in making it stand out.

[BruceJohnJennerLawso]

This is sort of half implemented now, since the planet is rendering at huge camera view scales. I think it will be fair enough to call this implemented once the vessel flag is rendered onscreen in camera view when zoomed out, and then we can just slowly cut off the Oxygen to the map view over time.

[BruceJohnJennerLawso]

also should make the +/- keys zoom the camera view in large increments so we can easily change camera scale while testing