Gives the calculation of the position of the magnet in the field of the OSEM coil to give maximum force/current and minimum cross-coupling from position of the coil to force.
-v1: initial version based on LIGO-T1000164
-v2: corrected coupling calculation; new calculation for BS flags with smaller magnets and BS-IM flags with double magnets
-v3: new calculation for BS-IM flags with magnetic disks