Move `lib/support.rs` to zinc crate -

Putting this functions into the top-level file seems rather natural, as
they are hierarchically a level higher  then this, and for the lack of
better name it seems rather okay to have them in `main.rs`.  As
discussed in #106, this remove a bunch of functions that are no longer
needed and only keeps the ones it doesn't compile with. It's been
verified that there no symbols pulled into the ELFs from anywhere that
would be the same as the ones removed by this change.