Added showdebug command.
Also:
* Added an exported constructor to RChildProcess so the iProcess handle was set to zero on construction.
* Fixed bug in fshell_builddocs script that created HTML relative links with backslashes instead of forward slashes.
=head1 FShell Documentation
L<Introduction|fshell::commands::fshell/Introduction> - an introduction to fshell.
L<Getting started|getting_started> - a guide to getting fshell up and running on various different platforms.
L<Change History|fshell::change_history>
L<Core FShell functionality|core>
L<FShell Commands|commands> - an A to Z of all the commands that fshell supports.
L<Plug-ins|plugins>
L<Developer documentation|internal> - documentation for developers wishing to extend fshell or write new commands.