Music plays, httpd responds in a snap, messaging subsystem works, full
end-to-end flash erase/flash/configure wifi & hardware/reboot to
squeezelite was tested.
CMake system works well: it now allows to flash in a single command
(assuming esp-idf V4.0 is properly installed on the system) with the
standard line:
idf.py flash -p <comport>
this makes building and flashing the app less confusing for new
developers/users wanting to experiment
