Debugger Terminal

No identifier Ack fix + Debug Terminal injection

[Fix: 8] Handling for PINGREQ that does not have ID but requires Ack-type PINGRESP
[Feature] Adding a DebugTerminal class to the MQTT Base library.

Connection Upgrade

MQTT Connection class now inherits from the common Connection base class, which merges the other libraries' dependencies into a common non-MQTT-related stack.

This is a breaking change to MQTT Stack 3.x, although a simple relink to class would suffice.
I'm reving up the major version to indicate that all the MQTT stack should follow to version 4.x

Bug fixes

Release Notes:
[Fix: 4] setConnected now executes even with upstream error
[Fix: 6] session process will not hang if some loops terminate.

Migration of Subscription and topic filters to Server project

[MQTT-6.0.0-1] Added error 55031 for Protocol Violation of type "Text Frame received over Websockets"

• Subscription and TopicFilter classes have been moved to Server library

Self-terminating sessions

Release Notes:

• Addition of public event for connection and disconnection
• Addition of "reason" code for disconnection
• Addition of "isSessionConnected" method to MQTT Base API
• Session now self-terminates inside the process (more consistent with fire & forget nature of the session within the MQTT Base class)

MQTT Connection and Base class abstractions

An abstract class for providing connection extensions for MQTT clients and servers, such as TCP, Websockets or Local Queues.