Allow commands after --help option.

Such that --help <cmd> will display a help page for the command. This
works seamlessly with the manual middleware so that help <cmd> shows the
man page whilst --help <cmd> shows the command help using the standard
gnu style format.
0.8.73
0.8.74
Disable trace by default.

And add EGENERIC error code.
0.8.75
Fix error wrapping tests.
Fix conflict between --help <cmd> and manual.

Such that the --help <cmd> logic does not override a previously defined
help command, so that the manpage(1) program now works as expected.
0.8.76
Segregate description and detail.

For information loaded from markdown definition files, so that the short
description is included in help output.

Requires work so that the man output also includes the detail information.
Update markzero dependency.
Improve description handling for man pages.
0.8.77
Remove debug statement.
0.8.78