Add subprocessing example showing how to create a pool object which communicates with multiple subprocesses
Clean up example
Further cleanups
Use select.select instead of select.Poll for Mac OS compatibility
Quite big simplification by getting rid of file descriptors
Nicer variable name
pep8ify rosenbrock
a few ignore tweaks
making the module PEP8 compliant
Some more PEP8 tweaking
Adding optional arbirary 'blobs' of data returned by lnprobfn
fixing a few indexing bugs with the blobs
Adding blobs example
adding a few comments to the blobs example
This commit helps backwards compatibility

* EnsembleSampler.sample and EnsembleSampler.run_mcmc now only return
  3 arguments when lnprobfn doesn't return any blob data.
Adding TypeError to lnprob output blob catching
making the assertion exceptions for number of walkers more explicit
Modified to run under python3.
 * Importing the print function from future and replacing all
   print blah statements with print(blah)
 * Setting a py_ver3 flag in the initialization of Sampler and
   Ensemble and then using that as a switch to chose between
   xrange (py 2.x) and range (py 3.x).
 * In ensemble.get_lnprob(), wrapping the call to Map (or
   the thread-pool aware version) in list( ) so as to get a
   vector back rather than a generator.
 * The tests all pass under python 2.7 and python 3.2, and
    all examples seem to work as expected except subprocess
   (which I have not tried).  Note that this includes a
   multithreaded option (rosenbrock), which produces the same
   results as the master branch version.
Remove py_v3 variable and just use python3 compatible code
rather than branching between python2 and python3.  This has
some cost in efficiency (e.g., the use of range instead of xrange
in python2), but is simpler.  For realistic scenarios the performance
penalty should be pretty small.
Merge branch 'py3' of https://github.com/aconley314/emcee into meta

Conflicts:
	emcee/ensemble.py
	emcee/tests.py