Merge pull request #13 from iambernie/tests

updated tests
added seperation between bodies as cmdline arg
added orbital_elements()
added tests for orbital_elements
Merge pull request #14 from iambernie/binarysystem

Binarysystem
pep8styling
Merge pull request #15 from iambernie/pep8

pep8styling
added prefix attribute to hdf5handler
tested and applied prefix
testing hermite dt_param
[do not merge] added sim_binaries
[do not merge] transfer only
added sim_veras_multiplanet.py
updated arguments
arbitrary nr of datapoints
bugfix: dset shape of scalars
print savepoints
added printdset() to misc.py
added more integrators to test veras_multiplanet
dt_param as cmd arg