When we are dealing with multiast, create the udp src and sink elements pointing
to the multicast addresses. When we are doing unicast, receive data on the local
ports and don't send RTCP because we don't know where we have to send it.
Fixes#583188
Original commit message from CVS:
* gst/festival/gstfestival.c:
Guard unistd.h with HAVE_UNISTD_H
* gst/modplug/libmodplug/load_it.cpp:
* gst/modplug/libmodplug/sndfile.cpp:
* gst/modplug/libmodplug/sndfile.h:
* gst/modplug/libmodplug/stdafx.h:
Support for compiling with MSVC: use _MSC_VER for detecting MSVC instead
of MSC_VER. Make CanPackSamples take the type it's passed. Change scope
of a variable in load_it.cpp to MSVC's scoping rules.
* gst/sdp/gstsdpdemux.c:
Guard unistd.h with HAVE_UNISTD_H
Fixes#544457.
