Added assertions to spot invalid call sequence for <freerdp_check_fds>
Added message queue custom free handler for input queue.
Split message handling and resource cleanup for input and update messages.
Added functions to free input and update queue messages.
Added assertions to detect invalid call sequences of <transport_free>
and <transport_disconnect>.
Added custom message resource free to update message queue.
Added <MessagePipe_Clear> and argument for custom handlers to
<MessagePipe_New>.
Added <MessageQueue_Clear> and custom handler argument to
<MessageQueue_New>.
Updated MessagePipe to new MessageQueue API.
Using new API for MessageQueue.
Using new API for message queue.
Using new API for message queue.
Merge pull request #1588 from akallabeth/message_queue_clear

Message queue clear