initial Use Case Doc
Added two more use cases
Added mindmap pics to UseCase Doc
Update UseCases.md

Made some additions/suggestions to sections 3, 6 and 7
Merge pull request #2 from JMLambert/UseCaseDoc

Update UseCases.md
May 20 meeting documents
Merge pull request #1 from ros-industrial-consortium/UseCaseDoc

Initial Use Case Doc for Review