FIX: Resolution convolution methods use incorrect indices
FIX: Resolution convolution methods use incorrect indices

Resolves #58

The weight of peaks were being shifted to higher energy due to incorrect indices being used in convolution methods. ResLib switches Qz and W indices, whereas neutronpy does not.

pseudocubic/neutronpy,granrothge/neutronpy,neutronpy/neutronpy,pseudocubic/neutronpy,granrothge/neutronpy,neutronpy/neutronpy