Macro debug

macro_rules! debug {
    ( $( $x:expr ),* ) => { ... };
}

Debug variables depends on environment variable DEBUG, using glob pattern to filter output.

e.g.

  #[macro_use]
extern crate debug_rs;

fn main() {
    debug!(666, 33, "aaa");

    debug!(vec![1, 2, 3]);
}

Then running:

DEBUG=*,-not_this cargo run // for *unix
// or
set DEBUG=*,-not_this; cargo run // for windows
// or
$env:DEBUG = "*,-not_this"; cargo run // for PowerShell