Atmosphere layer suffers from clipping

[AkeluX]

See #102 for the initial bug report. This is a known issue that we plan to address using an option currently in feature/camera. This will be done similarly as in Android here: https://github.com/NASAWorldWind/WorldWindAndroid/blob/master/worldwind/src/main/java/gov/nasa/worldwind/WorldWindow.java#L1023

In the meantime, you can artificially increase the far clip distance in Navigator.js in Navigator.prototype.currentStateForModelview:

this.farDistance = WWMath.horizonDistanceForGlobeRadius(globeRadius, eyePos.altitude);
this.farDistance += 1437568.7253136805; //<-- add this line
if (this.farDistance < 1e3)
    this.farDistance = 1e3;

[AkeluX]

Addressed by #118 with the workaround above