Simple macro that works just like C's ##

Why did nobody publish such crate before!?

It's literally 11 lines of code!

Example

```rust use clikeconcat::concat;

[derive(Debug, Eq, PartialEq)]

struct FuzzBuzz;

fn main() { asserteq!(concat!(0, x, 42), 0x42); asserteq!(concat!(Fuzz, Buzz), FuzzBuzz); // Sadly, but following code works // as stringify! will expand to "concat! (Fuzz, Buzz)", // not to "FuzzBuzz" assert_eq!(stringify!(concat!(Fuzz, Buzz)), "concat! (Fuzz, Buzz)"); }

```