Adding negation support to the s-ramp spec.
Incorporated feedback into spec WD from kstam.
Proposal to add ExtendedDocument and contentHash to the s-ramp spec.
Switch to SHA-1 hash.
File renames based on new JIRA issues.
Merge pull request #198 from EricWittmann/sramp-spec-negationAndContentHash

Added proposals for S-RAMP spec issues