- Add support for Pubsub Avatars
- Dont poll for vCard Updates, only use XEP-0153
- Dont cache vCards
- Store the avatar SHA of roster contacts in the DB
- Store the current SHA of each contact in the Contacts Object
- Move some code into the ConnectionVcard Class
A jid can contain characters that are not allowed in an action name.
This creates a unique UUID4 for each MessageControl and uses it as
action name instead.
We can reuse the UUID for other actions that belong to the
MessageControl
Fixes#8636