Created optimized version of AmoebaMultipoleForce kernels when all quadrupoles are 0
Merge branch 'quadrupoles' of https://github.com/peastman/openmm
Personal commit to make modeller easier to use
Merge github.com:leeping/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'quadrupoles' of github.com:peastman/openmm
Merge branch 'master' of https://github.com/leeping/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:SimTk/openmm

Conflicts:
	wrappers/python/simtk/openmm/app/modeller.py
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:SimTk/openmm
Merge branch 'master' of github.com:leeping/openmm
GBSAOBCForce adds an offset to the energy to reduce the discontinuity at the cutoff
CustomGBForces apply the same energy offset as GBSAOBCForce
Fixed an incorrect sign
Merge pull request #123 from peastman/gb2

Apply an offset to GB energy when using a cutoff to reduce the discontinuity
Improved error checking in ForceField