Fixes for Python 3 and installation.

[jgosmann]

These changes allow Spaun to be run with Python 3 by

• making relative imports explicit
• using function style print
• explicitly converting things to lists where Python 3 returns iterators

Furthermore, this fixes some paths so that Spaun can be installed as a Python package, but this commit does not include a setup.py to do so. (My ctn-archive/gosmann-frontiers2016 will include a setup.py which could be adopted. That file is a tiny bit more complicated because Spaun is pulled in as a git submodule and I have to do some package_dir foo.)

This is the minimal set of changes that were required. Certain configurations might require more changes.

Note: I haven't tested whether this produces still the appropriate results. I'm only interested in the run time for benchmarking.

[xchoo]

Hmm. Sweet. I'll test and merge when I'm done the thesis. 😄

[xchoo]

You might have to remind me in a month to do this 😆

[jgosmann]

That's fine. Take your time. Just wanted to make the changes visible if anyone looks for it.

[xchoo]

These changes should now be live in the v2.0 release.