Update package to support hwloc 2.2.0
A few things happened here which will break backwards compatibility:
+ bitflag fields were moved to the ffi package
+ Topology::new() & Topology::with_flags() are wrapped in an Option to
account for operation failures. Afaik, we dont' know how they failed,
just that they failed, so Option it is.
+ A lot of internal structures chagned (obviously)
+ Added a _ton_ of functions
It was quite a bit of work, but hopefully it works with 2.2.0 and
beyond!
