…ialize and test hash key presence everywhere we use it.
…it global pollution on Thread.current
…ferentiate affiliated sockets. Use strings rather than symbols. Move pid tracking onto the socket rather than in a lookup table, eliminating another point of potential GC breakage.
… to prevent leaked Thread references
…s. Don't default to creating a new socket per thread.
…nce it's causing problems with server 2.3.1