added inverted power potential (incomplete)
wrapped inversepower, added cpp test (incomplete)
added python test, not working
added tests
fixed inverse power and cpp tests
fixed python tests for inverse potential
Merge branch 'master' of https://github.com/pele-python/pele into inverse_power_potential
fixed documentation and removed tabs
fixed one more indentation issue
fixed indentation issues
fix indentation issue
fix a few more indentation issues
Merge pull request #59 from smcantab/inverse_power_potential

Inverse power potential
cleaned up cell list
Merge branch 'master' of https://github.com/pele-python/pele into cell_lists
fixed preiodic distance put_in_box
fixed some issues, still unsolved