New project template (issue #206)

I've added a `newproject_copy_me` folder with the basic files needed to create a new book and a README document (`README_new_book.rst` - see [here](https://github.com/isaacdontjelindell/runestone/blob/newproject-issue-206/README_new_book.rst) for a rendered copy).

I opted to add a separate pavement file in that directory to make it easy to build a new book - let me know if you can think of a better way of doing it.

I've also done some clarification and cleanup on the main readme, specifically in the section on installing web2py and dependencies. (and some typo fixes, etc).

Fixes #206.