Have all intermediate Python notebooks use same data files

Do to changes made after the introductory notebook was created, a
change in filename structure and contents was needed to keep the
lessons simple. This updates the intro lecture to use the same
files as the following lessons.
Rerun intro intermediate Python notebook using new files
Remove old intermediate Python data files
Template logic for setup instructions
removed comments that were completed above
Implementing Liquid contains for cleaner yaml list per @r-gaia-cs
comments to guide common bootcamp types
Init. commit of (medical) image processing ipynb.
Add height to Eventbrite iframe

and values for when using two rooms.

**The height provided isn't suitable for small screens.**

Close #493.
Initial commit
cleaning up README
Merge branch 'master' of https://github.com/swcarpentry/bc
Merging in swc master
Fixed reference link
Added link to Gnu Make manual
Updated language in intro module.
Added definition of graph to glossary
Testing makefile syntax hilighting mode
Testing makefile syntax hilighting mode 2
Revert "Testing makefile syntax hilighting mode 2"

This reverts commit e3871559de4dceee440036bd9a79265ea3596a53.
Revert "Testing makefile syntax hilighting mode"

This reverts commit 424320ee075457a2b2188c8ee168b902260bd989.