Fix startup issues with components using caps and vcards.
util/sasl/mechanisms.py: SASLMutualAuthFailed not defined

SASLMutualAuthFailed was not imported from sleekxmpp.util.sasl.client
Merge branch 'master' into develop
Fix setting publish options for pubsub storage.
Add XEP-0048 support
Merge branch 'master' into develop