Many changes were based on conventions in the Python socketmodule.
Changed many of the docstrings to match the Python socket library
conventions and enhancing them. I can either remove the prototype
part or add it to other docstrings in the library, depending on
feedback I get.
Changed setblocking to use the flag argument instead of always
just setting NONBLOCK.
Added enable/disable threading around more lwip calls.
Implementing optional backlog on listen().
Removing a few seemingly unneeded Py_INCREF(Py_None) calls.
Moved getblocking function based on alpha sorting of names.
