Fixes

Ensures calls to def/defp/defmacro/defmacrop are always qualified

(i.e. prefixed with 'Kernel.'), so they will also work in defprotocol modules or other places where the normal versions of these macros are hidden/overridden.

This fixes a bug reported on the Elixir forums by user 'belteconti'.

(c.f. PR #75 )