Added app! macro that can extract package name and version.
Opts can be parsed for the application root prior to launching handling
functions.
Added further integration with the console create
Improved display of description_lists, these now wrap the description
text.
Long and short opts are now optional and one or both can be used.
Environment variables can be checked for options/flags. The name of the
option is used to query if an environment variable exists for the given
option.
This can optionally be prefixed.
Added help generation for root and subcommands either using
`app help [command]` or `app --help [command]`
This help text displays all opts and their descriptions, available
subcommands and any description for the current command.