Macro erg_common::log

macro_rules! log {
    (info $($arg: tt)*) => { ... };
    (err $($arg: tt)*) => { ... };
    (info_f $output:ident, $($arg: tt)*) => { ... };
    (err_f $output:ident, $($arg: tt)*) => { ... };
    (f $output: ident, $($arg: tt)*) => { ... };
    (c $color:ident, $($arg: tt)*) => { ... };
    (f+c $output:ident, $color:ident, $($arg: tt)*) => { ... };
    ($($arg: tt)*) => { ... };
}

Debug log utility. directives: c: colored output f: file specified f+c: file specified and colored (e.g. colored output to stderr) info: info logging, (comprehensive shorthand for “c GREEN”) info_f: file version of info err: error logging, (comprehensive shorthand for “c RED”) err_f: file version of err