Remove deprecated stanza group extension

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Do not use CDATA inside e2e element (it's base64'd anyway)

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Fix roster match provider

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Public key publish provider

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>