formatting
use pele function to replace explicit loop
formatting
add product operator, use in harmonic
revert usage of product operator, maybe too much copying
add const, formatting
include order, formatting
add some harmonic cpp tests
add cpp test, harmonic interaction, energy
add test, formatting
Merge pull request #105 from kjs73/harmonic

Add more cpp tests for harmonic potential
improve benchmarking for cell lists
Merge branch 'master' of github.com:pele-python/pele
fix cpp test compile bug introduced in last commit
Merge pull request #109 from khs26/master

Pulling from pele-python:master on 09/12/14
Revert "Pulling from pele-python:master on 09/12/14"
Merge pull request #110 from pele-python/revert-109-master

Revert "Pulling from pele-python:master on 09/12/14"
Merge pull request #5 from pele-python/master

Pulling from pele-python:master on 09/12/14