Command-line application framework.

Example

A simple command-line application could look something like this:

```rs use rawcmd::{Command, Flag, Intent};

let app = Command::withname("foo") .withdescription("Command 1") .withflag( Flag::withname("flag1") .withalias("f1") .withdescription("Flag 1") ) .withsubcommand( Command::withname("bar") .withdescription("Command 1:1") .withflag( Flag::withname("flag2") .withalias("f2") .withdescription("Flag 2") ) .withresolver(|| Ok(2)) ) .withresolver(|_| Ok(3)) .run();

match app { Ok(v) => println!("OK: {:?}", v), Err(v) => println!("Err: {:?}", v), } ```

The function with_resolver accepts closures and function pointers:

```rs // closure command.withresolver(|| Ok(1))

// function pointer fn resolver(: Intent) -> Result { Ok(2) } command.withresolver(&resolver) ```

TO-DO