v1.4.2.0 fix gravgroup, extend HasEclipticLongitude

• Fix edge case in grav group: incorrect casting in the C code was causing planets that were too close to a sector boundary or another planet to be thrown back into the first sector.
• Remove cuspsToSectors.
• Add ability to set longitude in HasEclipticLongitude typeclass

What's Changed

• Fix gravgroup by @lfborjas in #41
• 1.4.2.0 by @lfborjas in #42

Full Changelog: v1.4.1.0...v1.4.2.0