Solve problem with plotting histograms of parameters with a huge range (1e20).

  - It may generate an approximate number of bins (probably due to rounding
      error).

  - A new function to generate unequal levels when the bins are not equal is
  necessary.

  - The new function must be exported and its arguments passed to globals.R.
Solve problem with ggs_geweke and the computation of the spectral density, where
in cases of series not changing values the ar() function gave an error.