Updating XMPP git
Add xep-cmr/metadata
Sync xep-cmr with official one
xep-cmr: Fix Schema
xep-cmr: add emacs settings
xep-cmr: Add note about difference to carbons
xep-cmr: Explain benefit in "use cases"
xep-cmr: Fix typo, s/available/active/
xep-cmr: Fix example, remove "'xmlns="