Note that all of the enum definitions changed (again?), and now they are
flattened into the 'bindings' namespace. This breaks the API in a way that
is relatively easy to fix, albeit annoying. Attempts to change the enum
generation using default_enum_style() resulted in endless compiler errors.
cargo test passes
Using the changes from @gadomski along with some additional work, to get the
generated bindings working again. Works on macOS and FreeBSD 11. A couple of
hacks are needed for FreeBSD, but nothing too serious.
Changed to use the libc prefix, and changed to use the generated enums.
Fixes#22, #15, and #14
cargo test passes
