collections of useful macros

example

```rust use useful_macro::*; //get argument and into Vec let arg = args!(); println!("{:?}",arg);

//get input and into String let s = input!(); println!("{:?}",s);

//power of two f64 number let p = powf!(2.,2.); println!("{:?}",p);

//split a:&str by b:&str and collect into Vec
let s = splittovec!("aa.bb","."); println!("{:?}",s); ```