clean up data subdir
remove old test for core.py
new generic function for reading sim data
stupid whitespace
moved unitsystem class into data/
import unitsystem from data
non-working modifications for adaptive steps
reworking particles
move units into misc subpackage
import unitsystem from correct location
remove particle class, clean up a few methods
working on using particles and orbits instead
only init tests
use new read_simulation func and unit_system
working tests to read in sgr data
remove old import
create tests and move units tests in there
use new lm10 reader
count nparticles after idx selection
unit_system not units