Changes

Fix launch to plane with negative inclination

Since #2112, the inclination fields in the constraints include the sign,
which is used to signal to the initial guesser that the initial launch
azimuth should be southwards. When passing this signed inclination to
the functions for calculating the angular momentum and eccentricity
vectors, this results in those vectors being calculated for an orbit
with a LAN 180° offset from the specified orbit.

This PR makes sure that the absolute value of the inclination is taken,
anywhere it is used for astrodynamics calculations; the initial guesser
is the only place where the inclination with sign is used. Fixes #2184.
 (commit: 5fdde24)