Multiple colormaps in contourf plots exported as eps

Two eps files of the same figure with different colormaps are merged to one.

FCT_EPS_EXCHANGE_AXIS is a workaround solution for the problem Matlab has
using multiple colormaps in one figure.
This function is a quick and dirty solution. It works without using the
packages 'freezeColor' or 'cbfreeze'. However, I do not know whether it
works with every GhostScript version.
I call it a dirty solution, because the actual problem Matlab exhibits is
not solved. Instead the resulting figure is obtained from two exported
eps-files of the same figure with different colormaps.

The way it works: From two eps files created from the same figure
using different colormaps this function reads from both the desired axes and puts it altogether to one eps-file 'out.eps'.

If the figure should have more than two different colormaps the 'out.eps'
can be again used with a third eps-file of the figure using another
colormap, and so on.