Merge pull request #34 from bjornstenqvist/master

Merge w. bjorn
Fixed nasty bug in `NonbondedVector::i2all`; fixed xcode compilation
error; added NaN check to `Movebase`; Stockmayer example no longer
returns nan energy but still minor problem with acceptance when
comparing to test case.
Fixed q2quad in multipole analysis; Added new Rotate/translate move for
clustered groups
Merge pull request #13 from mlund/develop

Fixed stockmayer nan energies