first pass of fixes for review comments
- don't 'exit' from option parsing, just raise appropriate errors
- moved option dump into a logging command in cli
- moved exiting on --help into the cli
- made it possible to send different array than ARGV to
  command_line_parsing
- reworked recursive print out of options
- reordered merge of options in host.rb (ensure that defaults is lowest
  priority)
- renamed 'defaults' to 'presets' as these are options that can come
  from env vars exported before a test run
- fixed broken spec tests