Initial commit for diffusion workshop talk

The talk uses impress.js, which is not part of the repository at the
moment. This commit just includes the first 3 slides.
Move css files to css/ directory
Renmae md file to slides.
Cleaing up file names and directory structure
generate graphviz dot diagram for workflow

 * cleaned up CSS removing useless items

 * added various classes in the CSS for images and shapes

 * changed pre class to be more sensible

 * adding images

 * added workflow slide

 * generated a Graphviz dot diagram for a scientific workflow
empty file
hello
Add Version and Event Control slides

The first half of the presentation is complete. The next stage is the
short Sumatra demonstration.

 * changed font sizes for headings, text, and code

 * increased overview size

 * removed comments

 * moved slides around

 * added "imagine..." slide

 * added Version Control and Event Control slides
Fix opacity issues and add Sumatra slides

Create class to enabled slide to be always shown even when the default
opacity is zero. Add 3 slides describing Sumatra

 * set the default opacity to zero for inactive slides
Finished all the slides

Provisoinal talk is now finished.

 * The slide with the triangle comes back into focus after each of the
   workflow, version control and event control.

 * Likewise with the imagine slide (comes back into focus) before the
   fantasy slide.

 * Fantasy slide is finished (could be better thought out)

 * IPython slide just shows a blog with a notebook and a sumatra record

 * Web interface slide

 * Thanks slide
Merge remote-tracking branch 'origin/master'

Conflicts:
	.gitignore