Delete generated diagrams and add third-party disclaimer

[jreina]

1. How can I delete a generated diagram? I was trying this out and didn't realize that an outline of my code was going to be shipped to a third party. This is proprietary information and must be removed immediately.
   After digging around it seems near impossible to take down diagrams. The issue has been raised with yUML

2. This package absolutely needs a disclaimer regarding sending data to a third party. While yUML.me is mentioned in the readme, it needs to be abundantly clear that the diagram generation is not being performed locally and can potentially be accessed by others.

[badihi]

It's a extreme case of privacy violation. I think github needs to take some action against such things.