Changed most instances of "remote_version" to "protocol_version", and

Changed most instances of "remote_version" to "protocol_version", and
others to "remote_protocol".  Downgrade the protocol_version if the
remote_protocol" is lower.  Output the protocol values if the verbose
level is large enough.  Exit if the user tried to force a protocol
value that is not within the range that we can handle.  Fixed the
output of the "very old version of rsync" message to output the right
Client/Server string.