A few helper commands that form the "dshell".
All commands are living in ./commands. A command cmd_name
lives in a file ./commands/<cmd_name>. The file should contain the following:
# @@ Command header, single line.
#
# @ A description of the command, potentially spanning multiple lines. This
# @ includes the usage.
# The actual command
echo "Hello!"All commands in ./commands will be loaded by when sourcing ./load. The
header will be listed in dhelp. The description will be shown with both
<cmd_name> --help and dhelp <cmd_name>.