Fixing star orbits (issue #92)

[AstroChara]

This is an attempt to fix the star orbits' radial orientation issue as reported by Issue #92: Reversed binaries in nearstars.stc.

Star systems fixed are:

• Luhman 16 (Mean Anomaly error)
• Sirius (mirrored inclination)
• Gliese 234 (mirrored inclination, eccentricity update 0.38 -> 0.382)
• Gliese 229 (mirrored inclination)

The current orientation of Gliese 65 appears to be correct (Gliese 65 B is receding relative to Gliese 65 A), and the change is left out.

[AstroChara]

Update 1: pedroJ suggested that the issue with Luhman 16 is ArgOfPercenter, and so that is implemented instead.

[ajtribick]

I think this looks good. Could you squash the commits?

[375gnu]

I have enabled squash commits and merged this into master