* Descriptions for readers, for better error reporting and usage help.
This also allows these descriptions to be multiline, and they're
indented correctly.
* A bit better formatting of options and defaults.
* Print full list of errors when there are more than one.
* #undef max
* Header as well as footer on single-line command help.
* Remove parse and parse_check variants I don't use.
* Allow processing without looking at argv[0].
* Optionally stop the processing at the first non-command, so that
you can have a program and its arguments without trying to parse
the arguments themselves.
baldurk