Now that we have version and authors macros we should add App::new_with_defaults that uses both

[rtaycher]

I think it's generally best to make cmdline parsing as simple and short as possible.

In that spirit I'd like to propose adding a way to initialize version/authors
implicitly since this would add make it more difficult to build an app without cargo
(although you could just define the 2 env variable manually) and since
App::new doesn't depend on it currently I thought people might be opposed to
changing it.

Instead how about adding a new method App::new_with_defaults?

[rtaycher]

Implementation

pub fn new_with_defaults<S: Into<String>>(n: S) -> Self {
    App { p: Parser::with_name(n.into()) }.version(crate_version!()).author(crate_authors!())
}

[kbknapp]

I think is a fine idea. I'd like to hear a few more opinions on the matter before adding it, primarily around the naming. I think new_with_defaults is kind of long. Maybe just App::with_defaults(name)?