Template for ipynb

Template for ipynb to make lessons have the same style of others
markdown lessons and necessary changes in Makefile since now
ipynb -> md -> html.

This come from @gvwilson.

Related to issues:

- [site/119](https://github.com/swcarpentry/site/issues/119)
- [site/321](https://github.com/swcarpentry/site/issues/321)
- [bc/179](https://github.com/swcarpentry/bc/issues/179)
Some improves in template

- Add input mark
- Add output mark

BUG:

- `output.text` in `stream` block end with new line character
Fix for ipynb template

- Escape all text input and output. This is require to avoid
  troubles with `<`, `>` and other characters that have special
  meaning in HTML
- Replace markdown syntax for images output with HTML
Seeding the intermediate material on Make
Seeding intermediate material on the bash shell
Redoing the slides without Bootstrap or Reveal in our repo
Updating slideshow
Fixing bad CDN link in slide layout
Merge pull request #252 from r-gaia-cs/ipynb-template

Template for IPython Notebook
Merging changes to master with new slides
Merge pull request #284 from gvwilson/novice-slide-decks

Redoing the slides without Bootstrap or Reveal in our repo
Incorporating suggestions from @r-gaia-cs
Merge branch 'master' into seeding-intermediate-make
Merge pull request #263 from gvwilson/seeding-intermediate-make

Seeding the intermediate material on Make
Merging recent changes from master
Incorporating comments from @r-gaia-cs
Merge pull request #264 from gvwilson/seeding-intermediate-bash

Seeding intermediate material on the bash shell
Merging changes from master