Explaining invasion percolation in lesson index
Trying to fix formatting errors
Importing sets and dictionaries material
Updating README to reflect actual structure
Renaming shell and git tutorials to allow for others beside them
1. Importing Python debugging tutorial from Anthony and Patrick (via the 'restructured' branch in the old repo).
2. Getting build errors in lessons/python-debugging/tutorial.md, but can't diagnose (no line numbers in error messages when run in Jekyll, and Maruku seems to stumble on Pygments highlighting).
Importing more material from The Hacker Within
Switching to redcarpet for rendering: let's see how this works on GitHub
Removing rusty instructions from README
Merge pull request #4 from gvwilson/gh-pages

Switching to redcarpet for rendering.
Starting to import IPythonBlocks-based intro to Python, and cleaning up random HTML in other places
Notebooks from intro to Python with blocks
Renaming for consistency
For loops using IPython Blocks
Updating lesson material imported from THW
Merge branch 'master' of github.com:swcarpentry/bc into gh-pages
IPython Notebooks for the blocks-based intro to Python
Merge branch 'gh-pages' of github.com:swcarpentry/bc into gh-pages
This file should not have been added in the first place
Coverting another section of the blocks-based intro