- Create new install.rst for Installation, making a local Demo applicati...

...on, and a reference to HACKING.txt.

- Move sections on Installation, Demo into install.rst.
- Unlink "pyramid" reference in docstring of evolution's __init__.py so that docs will build.
- Update link in theme to use install.html
- Closes #134
I considered that idea, but HACKING.txt is targeted more toward contributors/hackers than explorers/curiosity seekers.