connections from the VDQM and one for listening to connections from RTCPD.

Two ports are required because of the major differences between the VDQM and
RTCOPY prototcols.  In the case of the VDQM protocol, the tape aggregator
should listen, accept and then read in an incomming VDQM message, in other
words the magic number, request type, message body length and finally the
message body.  In the case of the RTCOPY protocol, the tape aggregator should
listen, accept and the send as opposed to read in a message.

Fixed Imakefile so that it compiles dlf in the dlf directory and common in the common directory (they were buidling each other in each other's directory????), and added the right depth (right number of ../) to the location of the dependent library directories.  Added RTCPDErrorMessage exception.

to propagate errors through function calls.

all of the command-line arguments concatenated into a single string.

Marshaller code can now safely unmarshall strings.  Unlike the orginal C code, the new string unmarshaling code checks both the source and destination buffers.  The original C code did not check the source buffer and a server could crash on reception of a message containing a string with no terminator character.