Issue 33: Message formatting proposal

In the TC meeting of September 20, we discussed allowing certain messages defined by the
SARIF specification to contain formatting information, rather than being restricted to
plain text.

I have uploaded a proposal to address this issue. In the OASIS TC SARIF GitHub repo,
please see the document Documents/ChangeDrafts/sarif-v1.0-issue-33-gfm.docx:

https://github.com/oasis-tcs/sarif-spec/blob/master/Documents/ChangeDrafts/sarif-v1.0-issue-33-gfm.docx

In particular, please see the following change-barred sections:

3.10 Message properties, p. 18

This section distinguishes between plain text messages and messages with formatting.
It specifies GitHub Flavored Markdown as the formatting language. It offers security
guidelines for processing Markdown.

The remaining changes specify whether each "message"-like property is restricted to
plain text or permits formatting:

3.17.5 result.message property, pp. 36-37
plain or formatted

3.22.2 codeFlow.message property, p. 51
plain

3.23.2 stack.message property, p. 51
plain

3.24.2 stackFrame.message property, p. 52
plain

3.25.8 annotatedCodeLocation.message property, p. 55
plain

3.26.2 annotation.message property, p. 64
plain

3.27.5 rule.shortDescription property, p. 65
plain

3.27.6 rule.fullDescription property, p. 65
plain or formatted

3.29.2 fix.description property, p. 67
plain

3.32.6 notification.message property, p. 71
plain

3.33.3 exception.message property, p. 72
plain

I'd like to discuss this at tomorrow's TC meeting.

Thanks,
Larry