Adding two functions to find the optimum rotation solution using
spherical harmonic decomposition in the ElectronDensity class
To align a pose to a map
1. call poseSHT(), which will return poseCoefR and poseCoefI
2. feed mapSHT() the two "poseCoefR and poseCoefI" to get a rotation
matrix and a score
Future Work:
Add a wrapper to combine the two functions into one function "fastAlignPose".
The reason to have two functions was because it was used in a grid search of the whole map,
where I don't want to calculate poseCoefR and poseCoefI again and again.