Fix for cython v0.20+
Use ao_hash_map for identifier_generator.
add poll_fd() to C++ client.

Signed-off-by: Sean Ogden <positivelyskewed.sf@gmail.com>
Merge branch 'master' of git://github.com/seanogden/HyperDex

* 'master' of git://github.com/seanogden/HyperDex:
  add poll_fd() to C++ client.