Changed fft dependency

Changed the fft dependency from jdk-mines to jtransform.
https://github.com/wendykierp/JTransforms
Added NextSmoothNumber utility

A class to determine the next smooth number.  This is required so that
we can find the fast fft sizes.  Research and implemention performed by
Johannes Schindelin.
Changed FFTMethods to use jtransform
Added new tests