chmod u+w on bundled libzmq

sometimes libzmq has weird 444 permissions, preventing otool patch
remove global CONFIG state

- configure command handles all configuration
- all build / conf / temp files are written in build_base (#318)
minor fixes
Merge pull request #319 from minrk/buildtemp

Try Configure again (take a million)

Now all detection / config loading is done inside the Configure command.
It should hopefully be a little bit easier to follow the order of events.

All build / conf / temp files should be written in build_base (see #318)

Should also address the issue of requiring setup.py build bdist_egg in order to get bundled libzmq.dylib into the tree.

closes #318