Fix missing spice call for body[8] in first runs.
Caused unnecessary time steps in the beginning.
Increase number of saved states for planetary encounters
- n is reduced if a significant part of the acceleration is not caused by the sun.
- CMake option: SaveRateOpt
SaveRateOpt refinement:
- only compile function when needed
- only run function during the saving period
Misc. cleanup of RK76:
- remove body[9] (not needed since always identical to body[8]
- Comments, formatting
Major fix of Integrator:
- Wrong sign in equation caused major error.
- Interpolation formula was mis-optimized earlier.
(- Better commenting)
Merge branch 'md_RK76' into GSOC-Integrator

Conflicts:
	Particle_Integrator/Code/Integrators/RungeKutta67.h
Merge branch 'GSOC-Integrator'
Rename integrator for consistency, typo.
- RK67 > RK76 everywhere.
Merge branch 'md_RK76' into GSOC-Integrator
Print beta-corrected solar GM (useful for plotting semi-major axis),
other corrections.
Improve algorithm:
- Far less sensitive
- Fix possible integer division by zero bug
- Fix implementation in RK76
Merge branch 'md_SaveRate' into GSOC-Integrator
Merge branch 'GSOC-Integrator'