Crossbar

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* new: 1607 component restart behaviors (1623)
* fix: bump Twisted to v19.7.0 because of CVE-2019-12855

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* fix: wait for onJoin to run in start_router_component (1613)
* fix: worker disabling from env var (1612)
* new: load node cryptosign key on all native workers
* new: `max_message_size` for both listening and connecting transports
* fix: improve reading config values from env vars
* new: worker option `disabled` to skip starting of worker
* new: router statistics tracking and management API (`get_router_realm_stats`)

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* new: WAMP meta & CB mgmt API - close router sessions by authid/authrole
* fix: turn down log noise for detaching sessions already gone
* new: allow setting authid in anonymous auth; remove setting authid/authrole from client params on anonymous auth
* fix: system/host monitor typo in stats attribute
* fix: REST bridge (1597)
* fix: WAMP meta API guard session attribute access (1594)