GPSD can now be a gpsd client

that is, it can connect to and relay data from other gpsd
instances. Sample usage

	# gpsd -S 12000 -n 'gpsd://localhost:2947/?raw'
	# cgps 127.0.0.1:12000

1 files changed, 16 insertions, 13 deletions

diff --git a/gpsd.xml b/gpsd.xml
index 09b4fe90..eaf4e09d 100644
--- a/gpsd.xml
+++ b/gpsd.xml
@@ -186,19 +186,22 @@ to standard error if <application>gpsd</application> is in the foreground
 Normally, a data source is the name of a local serial device from
 which the daemon may expect GPS data.</para>
 
-<para>A data source name may also be a URL pointing to a specific
-differential-GPS service (DGPSIP server or Ntrip broadcaster).If the
-URL starts with "ntrip://" Ntrip will be used; if the URL starts with
-"dgpsip://", DGPSIP will be used.  <application>Gpsd</application>
-also defaults to DGPSIP if no protocol is defined.  For Ntrip services
-that require authentication, a prefix of the form "username:password@"
-can be added before the name of the Ntrip broadcaster.  If a suffix of
-the service name begins with ":" it is interpreted as a port number,
-overriding the default IANA-assigned port of 2101.  For Ntrip service
-you also need to specify which stream to use; the stream is given in
-the form "/streamname". So, an example DGPSIP URL could be
-"dgpsip://dgpsip.example.com" and a Ntrip URL could be
-"ntrip://foo:bar@ntrip.example.com:80/example-stream". <!-- If this
+<para>A data source name may also be a URI pointing to a specific
+network GNSS service (GPSD server, DGPSIP server or Ntrip broadcaster).
+If the URI starts with "ntrip://" Ntrip will be used; if the URI starts
+with "dgpsip://", DGPSIP will be used; if the URI starts with "gpsd://",
+gps protocols will be used. <application>Gpsd</application> defaults to
+DGPSIP if no protocol is defined. GPSD URIs take an optional argument to
+select the wire protocol: raw, nmea or gpsd - these correspond to "R=2",
+"R=1" and "w=1" modes. For Ntrip services that require authentication, a
+prefix of the form "username:password@" can be added before the name of
+the Ntrip broadcaster.  If a suffix of the service name begins with ":"
+it is interpreted as a port number, overriding the default IANA-assigned
+port of 2101.  For Ntrip service you must specify which stream to use;
+the stream is given in the form "/streamname". !n example DGPSIP URI could
+be "dgpsip://dgpsip.example.com" and a Ntrip URI could be
+"ntrip://foo:bar@ntrip.example.com:80/example-stream". A gpsd URI could be
+"gpsd://gpsd.example.com:12000/dev/gps1?raw". <!-- If this
 option is not given, <application>gpsd</application> will hunt for a
 DGPSIP server. --></para>