Fix bug in MEM function that may produce a memory leak. (function returns NaN array)
Added support for multiple fitting functions (easily extensible): Lorentzian, Assimetric Lorentzian and Dumped harmonic oscillator functions available.
Added support for calculating FFT/correlation in GPU using CUDA c extension.
Added fitting to normal distribution in the atomic displacements analysis
Minor changes to the API
Other minor corrections and fixes