0.4.1:
  Updated the references in the documentation

0.4:

  * feature: compute the 2-point correlation function in easyeq.

  * feature: compute the Fourier transform of the 2-point correlation function
             in anyeq and easyeq.

  * feature: compute the local maximum of the 2-point correlation function and
             its Fourier transform.

  * feature: compute the compressibility for anyeq.

  * feature: allow for linear spacing of rho's.

  * feature: print the scattering length.

  * change: ux and uk now return real numbers.

  * fix: error in the computation of the momentum distribution: wrong
         definition of delta functions.

  * fix: various minor bugs.

  * optimization: assign explicit types to variables.