* The mdns responder has been reworked to lower stack and memory usage. This is
a variation on the upstream code, it use malloc whereas the upstream code uses
pools. The high stack usage of the mdns responder was problem for
esp-open-rtos, so we might have to maintain the differences for now.
* Improved lwip core locking, and lock checking. Upstream improvements, that
need some added support from esp-open-rtos specific code. More core lock is
performed when calling from the esp-open-rtos code now, so a little safer. The
checking is not enforced, but projects might see warning messages and might
want to look into them.
* The esp-open-rtos lwip support has been sync'ed with the new freertos port
included with lwip. There are still some minor differences.
* A few lwip timer bugs have been resolved. This might help resolve some issues.
* Plus it picks up all the other upstream fixes and improvements.
* The default lwip stack has been lowered from 768 words to 480 words,
due to the reduced stack usage by the mdns responder.
Relies on global flags set when the user ISR is executing.
Unclear if this fixes any bugs as ISR code may not have been calling
into LWIP, but the previous implementation was broken.
