Compile with nightlies

Hello,

Here is a patch to fix issue #10 I opened this morning (at least it was the morning in France ^^)

It's not really idiomatic rust, but at least does it compile.

I think one problem is the overlapping of the operator-overloading macros. Maybe would it be better to `include!` them directly in the related file? I'm a Rust newb, so maybe it's plain stupid, but at least it wouldn't pollute the global namespace.