shoehorning the rust-empty Makefile to my needs
Result-i-fication of the `Formatter` interactions

due to introducing the `output: &mut Writer` to `Formatter`, coupled with
the addition of `-D warnings` for compilation, this ended up happening
in order to properly deal with & propagate any errors that may occur..
I wonder how much parse/lexer error stuff is being swallowed up in the
libsyntax API?