Fixed problem in commit d790478f3b11e412fe3f0d47aed84464920ccf31.
    Second bind() will fail but it is ok. Must bind to IP=INADDR_ANY
    for receiving of multicast to work.

	modified:   udpmcastreceiver.cpp
    Add UDP unicast receiver and test. Not tested yet.
    Uses slightly modified multicast receiver to receive
    UDP unicast.

	modified:   Makefile
	modified:   mcastrecv_test.cpp
	new file:   udpreceiver.cpp
	new file:   udprecv_test.cpp