This will be the namespace crate for all the various fog-* projects, assuming
that any of the "packages as namespaces" RFCs come to fruition (ex.
[Manishearth's namespacing RFC][rfc]).
Alternately, if packages as namespaces never happens, this will serve as an
umbrella crate for fog-* projects, re-exporting them for use and grouping them
behind feature flags as needed.