fix redshifting wave_list bug and add roundoff error guard
simplify ChromaticObject.draw integrator decision and _applyMatrix ChromaticSum decision
Merge branch 'master' into #520
Add tests for SED roundoff guard and redshift bug fix
(#520)
Flesh out the tests for this branch a bit more
(#520)
Merge pull request #521 from GalSim-developers/#520

#520 sed bug fix / chromatic aesthetics tweak
Merge branch 'master' into #524