JPL DE ephemerides: initial commit of structures, routines etc.
DE: added Example to test Sun position output. Fixed a ton of bugs.
JPLephem: changed struct/func names to follow LGM convention, updated example prog

NOTE - there is likely a small memory leak in using the position calculation.
This should be checked with Valgrind before integration with the main branch.
JPLephem: added test cases to DEQuickStart and exercised other objects
JPLephem: cleaned up typos, fixed memory leak.
JPL ephem: More examples, added routines for Earth pos (ICRF) and Earth-Sun vector (GCRF)
SUN: test Lgm sun vector against DE421 instead of unknown JPL ephemerides
JPLephem: added test (against JPL testpo.421), fixed bug in saturn call, set MOON_ICRF
LCDS: removed debugging exit statement in LastClosedDriftShell tool.
JPLephem: fixed Makefile to install DE data files, moved pathing in line with install
Merge branch 'mms'