Added ==smoke-test support and ciftest command.
Commands can now define a "==smoke-test" section in their CIF files, which defines a snippet of fshell script that will be run as part of "fshell smoketest" or by invoking ciftest directly. See the ciftest documentation for more details.
Added ==smoke-test sections to a few commands, the ones that were easy to test!
=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.