Improved Scenarios document
Added diagrams for scenarios.
workflow: diagrams are contained in the osdi-scenarios-diagrams.pptm
run export_slides macro
if a slide has a text box named "title_text" then the text value will be
used as value.png for the output filename.  If the slide doesn't have this
text box, then the slide is skipped.
Add new OSDI tab to ribbon.  Image Export button is on that ribbon tab
link to scenarios from readme.md
Merge pull request #114 from wufm/feature/requirements

Feature/requirements Diagrams