IMPORTANT: optima_fft now uses ifftn(), not ifft()

This appears to have been a bug in the original PLoS One code. The
result of the inverse FFT does not return information in the ‘real’
data space, but in the Fourier space still.
Documentation
REVERTED extraction of mirror_edges()

This refactoring was NOT transparent, but introduced errors.
Corrected optima_fft package.
Enabled default scales
Enabled logging/plotting