Modified the nodemanager to include the simplest version of Affix integration.
Addressing issue #137 on the Seattlelib_v2 repository. Changed various files to use dy_import_module instead of using dy_import_module_symbols.
Changing the default nodemanager Affix string to use the new MakeMeHearAffix.
Update `nmmain.py` to use the latest Affix version; cleanup.

* Updates to reflect the latest changes in the Affix framework,
  e.g. affixstackinterface --> affix_stack, NatPunchAffix -->
  MakeMeHearAffix, remove "Zenodotus name" and advertisement
  as these will be handled by the NamingAndResolverAffix.
* Removed remnants of the (non-working) TimeoutAffix. Use
  the Repy sockettimeout library instead.
* Slightly clarified the main listenport-searching loop. It now
  reacts differently when encountering "typical" listen errors,
  and retries more quickly.
* Made the builtin check for IP address changes conditional on
  whether Affixes are enabled. (If they are, then NamingAndResolverAffix
  will do this). --- This is actually a hint at refactoring
  NamingAndResolverAffix and move its IP change monitoring function
  into a library other programs can use.
* Minor code cleanups
* Docstring fixes
Removed blanket except that is supposed to catch SocketTimeoutErrors; unrelated cleanup.

This was implemented as a stopgap solution for SeattleTestbed/portability#28.
A less error prone variant would have been to check `str(exceptionobject)`
for the name of the expected exception; the blanket except has been
dening me around in circles during debugging...

I'm disabling it for now. I'll implement the suggested name-in-str
fix until the root cause with `dylink` is fixed.
Work in progress: Get the inclusion of Affix right. Also, unrelated cleanup.

Lots of the overriding etc. stuff has been on this branch before,
but I believe it was never tested. E.g., the nodemanager's listening
socket was wrapped using `sockettimeout`, but the wrong wrapper.

Other than that, added a few debug statements to see which network
calls are actually used, and added a few spaces between operators
here and there.
Make nmconnectionmanager fail on unexpected errors. nmmain now has logic to detect this and restart.
Remove debug messages; check that the accepter thread is running (and restart it if not).

Previously, this restarting functionality was implemented in the
check for IP address changes. Now that NamingAndResolverAffix
does the check, we need a different way to find we should restart
AccepterThread. Also, I don't see that previously, an AccepterThread
that became invalid (e.g. TCPServerSocket not usable anymore due to
IP address change) would ever be stopped.
Updated unit tests to conform with latest Affix release.

Also fixed a few obvious import / module name problems.
Merge pull request #97 from aaaaalbert/affix_nodemanager

Affix nodemanager