Iterates the messages and priorityMessages arrays of each plugin. If a quit message is found, its content is returned.
Note: The message arrays are not nulled out in this function.
Array of plugins to iterate.
The content of a quit message, if one was received, otherwise an empty string.
Iterates the messages and priorityMessages arrays of each plugin. If a quit message is found, its content is returned.
Note: The message arrays are not nulled out in this function.