aviator usage/output streamlining

- format aviator output
- allow setting default via default: true, or assume first
  - also add a * in UI to default
- allow overriding a value with user inputted string
streamline UX - only show configuration choices

- if just one option (default) hide the service entirely
  (TODO: may want to make this possible to manually override
  later, e.g. if just one pre-configured option for DB
  url but sometimes user wants to specify their own without
  updating the aviator.yml)
- removed / reorganized output of text. Moved most to Verbose
  level instead of Normal
getSetupOptions - cleanup method comments
Merge pull request #19 from Clever/ux-improvements

aviator usage/output streamlining