test: fix spec issues to meet paho test runs

Fix paho failing tests (#174)

fix: SignalDisconnect before SignalOffline
Handles case when Disconnect from client provides SessionExpiryInterval

fix: tag name for RetainAvailable parameter
fix: send the username to ACL on publish
refactor: check for topic alias when the packet arrived
  prevent double-checking for ACL
refactor: decrement children count on node delete
refactor: set publish stub before unsubscribing
fix: fix to #173
  Shutdown subscriber when the session expire fired.
  Prevents subscriber from leaking.
refactor: incoming PUBLISH messages
  handle flow control as per spec

fix: return of granted QoS
refactor: send disconnect from connection close stage 2 only
refactor: clone PUBLISH packet before sending from a topic manager

v0.4.0-rc.7: improve listener configs

Allow listeners to define its TLS section. Listeners ssl & wss are declared as deprecated

v0.4.0-rc.6

doc: improve README ref #146 (#157)

v0.4.0-rc.5: ci: pass variable name instead of value

Signed-off-by: Artur Troian <troian.ap@gmail.com>

v0.4.0-rc.4: ci: run docker/check to login in registry

Signed-off-by: Artur Troian <troian.ap@gmail.com>

v0.4.0-rc.3: ci: start job with capital

Signed-off-by: Artur Troian <troian.ap@gmail.com>

v0.4.0-rc.2: ci: use docker_job for for docker builds

Signed-off-by: Artur Troian <troian.ap@gmail.com>

v0.4.0-rc.1: ci: rename docker stage

add lint to release stage

Signed-off-by: Artur Troian <troian.ap@gmail.com>

MQTT V5.0

• V5.0 specification
• Turn persistence to be an interface derived by other implementations

Optimize goroutines and memory usage

Decrease amount of goroutines per connection. Now only receiving routine is always active with respective buffer. Send is only activated when there is some data to flush