Revert "Get rid of fftw dependency"

This reverts commit 7a6d91f566b9271e91f82d97724805993c8f8663.
Fix linking against static libfftw3f
readme.rst: dct parameter is back
Call emms before returning from Analyse and Recalculate

The mmx functions from x264 don't do it.

Fixes crashes with block width of 16 or lower.