[Proj] Fixes to minor problems with geodesic routines

[Charles Karney]

I've committed an update to the geodesic library...  Log message it

Update to version 1.43 of the geodesic routines.  This fixes two
relatively obscure problems.  (1) The business of returning an unrolled
longitude with the solution to the direct problem was broken for
west-going geodesics.  (2) For flattening > 1/100, a slightly inaccurate
result was returned for a12 in the direct calculation.