change haskell category

Not that I'll necessarily upload this (unless I need to for debian packaging),
but it looks a little weird to see 'Apple' here :)
use autopep8 to format the generated code

This is quite slow (adds 30s to building the bindings which previously took
<2s), but it is handy for debugging to have everything not all mashed together.
If I can't handle it, I may just move the autopep8 to the 'release' target and
only do it when releasing.

Closes #24
Keep iov_base alive

Keep `xcb_parts[0].iov_base` alive using cffi_explicit_lifetime
Re-add ensure_connected decorator to send_request

Here be dragons