new clisp packages

[Bruno Haible]

Two things about the clisp 2.49.60 release:

  1) It MUST be configured with --enable-portability.
     Without it, currently there are no guarantees that it will build and
     run without crashes, on any platform.
     This option disables a number of optimizations, but has shown good
     success in avoiding the various FTBFS.
     But I guess that, especially for the 'unstable' branch of Debian,
     a clisp that runs more slowly is more acceptable than a clisp that
     does not build or exhibits crashes.

     The current plan is that this option will not be necessary any more
     in version 2.50.

  2) Modules other than i18n, syscalls, regexp did not receive much attention
     for some time and are not in the focus of version 2.50 either. That's
     a TODO item for post-2.50.

Bruno