Packaging

First thing : this project is awesome !

Here is a **draft** of a packaging pull request.
I added a `setup.py` file so that you can push your project on PyPi in an instant.
I also added a `requirements.txt` if someone wants to use Webalchemy without using `setup.py`.

The big change is that pythonium and tornado are not anymore in this repo. For now, i'm just grabbing the upstream packages but i saw you made some changes to upstream so maybe it will not be possible to do that (for now, my pull requests "woks" but some things like slices in js are broken)

A possibility would be to fork thoses 2 repos (on https://github.com/webalchemy, is it yours ?) and make the changes you made on thoses forks. Packaging would still be possible with ` pip install -e git+https://git.repo/some_pkg.git#egg=SomePackage` but the huge win is that you may push your changes upstream (if they are ok) and pull new versions in a breeze

Some slight other changes are : 
* Some better PEP8 compliance 
* Moving `webalchemy/examples/` to` examples/` (for now, i made a slight hack to be able to import webalchemy but i think a could find a better way to do this)
* Fix the tornado url in the readme

So, there it is :)
I think my pull request should not be merged (at least not in master) because it makes some regressions. I submitted it to see if you are interested and i'm of course willing to fix it :)

Edit : packaging is still a draft too, it's still missing a setup.cfg, manifest and a bit of testing but it looks like it's working (ie. `./setup.py install` works)
Edit2: also fixed some self imports like : `from webalchemy.examples.hello_world.hello_world_example import HellowWorldApp`

Note : I'll be abroad from tomorrow (17/01) for ~1 week so i wont have much time next week to check answers and respond, sorry :/ (might even not have internet)