Fixed EM fit for large kappa

- Fix: Large kappa where messing up the fitting process. Now large kappa switch to a Gaussian component (great approximation anyway, assuming you're around mu = 0.0). Also removed some non-convergence checks. It's handled by LL being higher anyway… Need to rerun all fits though
Fixes for new EM fitting

- Fix: Misbinding reloader now produce good plots for Mixt Model results
- Added: new Generator for Specific stimuli, using the fixed EM fit code.
- Fix: Modified lunahcers_specificstimuli to put num_repetitions as last dimension of result array. Makes it compatible with multiple reruns concatenation