Moved non-loadable pickles from pickles/ to pickles/future

[Jose E. Marchesi]

Hi people.

Many of the pickles in pickles/ do not load because they use some
facility that is not yet implemented, while others use weird syntax and
concepts that predate the current form of the language; I wrote these to
get an idea of what I wanted/needed.  A few others are incomplete or
mere skeletons.
    
To avoid people getting confused (especially in this early stage where
we do not even have a manual) I am moving all the pickles that cannot be
loaded to pickles/future/, and changing the build system to not install
them nor to put them in the distribution tarball.
    
As we support more features, we can move/adapt the files from
pickles/future back into pickles/.

Salud!