Fix line in rel notes
Update README.md
Update RELEASE-NOTES.md

Fix broken links
Update RELEASE-NOTES-2.0.md

Synce RELEASE-NOTES as a follow up to c7b9b4ffe310e0d339b40bd1668393df5657f24c
Merge branch 'master' of ssh://wmfgerrit/mediawiki/extensions/SemanticMediaWiki