Expand language introducing conditional loops

Also, changing wording on prison slightly
Add a new section on the "programs needed".

We've seen this many times before - people can get
python, but don't know what to use to write it.
So I've added a section on good code editors to use.

They're specifically not IDEs.

This also allowed reorganising the last section of the
page to be more compact and easy to follow (less broken
up by the dialogue boxes)
Add a new page on "Where to go"

Or, how to continue learning python, and what to do with it.

In the future it might also be expanded to show some particular
parts of the language, and libraries, where python shines for
getting cool stuff done. Like PIL, SciPy, iPythonNotepad, Flask,
etc.