Move `lib/support.rs` to zinc crate

Putting this function into the top-level file seems rather natural, as they are hierarchically higher level to then this and for the lack of better name it seems rather okay to have them in `main.rs`.

I have tried to rename `main.rs` to `lib.rs`, as it appears to be the current convention, but it screwed the hell out of rake and it blew up with "stack level too deep" exception, which I found quite funny...