Partial fix Issue #876 and improvements in Multiple Shooting
Summary of changes in AbstractMultipleShooting
- Fix sign of epoch partials
- Avoid computation of inverse of Jacobian
- Allow for under-determined linear systems
- Added possibility to scale the linear system based on a reference time and length
- Allow for different duration of trajectory arcs
Moved methods related to closed orbit constraint to CR3BPMultipleShooter
class since the constraint is not enforced by the other implementations. Added unittest to check it is working correctly.