Add a Nano installer for Windows

1. Downloads and installs Nano into the users home directory
2. Adds Nano to the path
3. Makes Nano the default editor
Switch from using .bashrc to .bash_profile nano path and editor export
Append exports to end of .bash_profile instead of overwriting

In the process at an explanation of where the lines came from
so that users know they can remove the lines if desired.
Remove testing line
initial func and modules copy from bootcamps
Anthony's updates to functions and modules.
added Aron's edits.
converted docs tutorial to ipynb
updated tutorial
added forgotten rst files for example.
Another version of the code
Merge pull request #24 from scopatz/funcmod

Added Functions and modules to Python lesson
Merge pull request #26 from scopatz/thw-docs

Converted thw-docs tutorial to IPython notebook.
Merge pull request #35 from ethanwhite/gh-pages

Add a Nano installer for Windows
Simplifying the final example
Merge branch 'gh-pages' of github.com:swcarpentry/bc into gh-pages