Update source file names in comments and docs.

Correcting a source file name in the docs just now reminded me that
I've seen a lot of outdated source file names elsewhere in the code,
due to all the reorganisation since we moved to cmake. Here's a giant
pass of trying to make them all accurate again.

ssh/gss.h

@@ -32,7 +32,7 @@ typedef gss_name_t Ssh_gss_name;
 
 #define GSS_DEF_REKEY_MINS 2    /* Default minutes between GSS cache checks */
 
-/* Functions, provided by either wingss.c or gssc.c */
+/* Functions, provided by either {windows,unix}/gss.c or gssc.c */
 
 struct ssh_gss_library;
 

ssh/server.h

@@ -137,7 +137,7 @@ int platform_make_x11_server(Plug *plug, const char *progname, int mindisp,
 
 Conf *make_ssh_server_conf(void);
 
-/* Provided by Unix front end programs to uxsftpserver.c */
+/* Provided by Unix front end programs to unix/sftpserver.c */
 void make_unix_sftp_filehandle_key(void *data, size_t size);
 
 typedef struct agentfwd agentfwd;

ssh/sesschan.c

@@ -230,7 +230,7 @@ Channel *sesschan_new(SshChannel *c, LogContext *logctx,
     sess->conf = conf_new();
     load_open_settings(NULL, sess->conf);
 
-    /* Set close-on-exit = true to suppress uxpty.c's "[pterm: process
+    /* Set close-on-exit = true to suppress pty.c's "[pterm: process
      * terminated with status x]" message */
     conf_set_int(sess->conf, CONF_close_on_exit, FORCE_ON);
 
@@ -303,7 +303,7 @@ static void sesschan_start_backend(sesschan *sess, const char *cmd)
      * will be set as part of X or agent forwarding, and shouldn't be
      * confusingly set in the absence of that.
      *
-     * (DISPLAY must also be cleared, but uxpty.c will do that anyway
+     * (DISPLAY must also be cleared, but pty.c will do that anyway
      * when our get_x_display method returns NULL.)
      */
     static const char *const env_to_unset[] = {
@@ -560,7 +560,7 @@ bool sesschan_send_break(Channel *chan, unsigned length)
 
     if (sess->backend) {
         /* We ignore the break length. We could pass it through as the
-         * 'arg' parameter, and have uxpty.c collect it and pass it on
+         * 'arg' parameter, and have pty.c collect it and pass it on
          * to tcsendbreak, but since tcsendbreak in turn assigns
          * implementation-defined semantics to _its_ duration
          * parameter, this all just sounds too difficult. */

ssh/sharing.c

@@ -1177,7 +1177,7 @@ void share_got_pkt_from_server(ssh_sharing_connstate *cs, int type,
       case SSH2_MSG_REQUEST_SUCCESS:
       case SSH2_MSG_REQUEST_FAILURE:
         globreq = cs->globreq_head;
-        assert(globreq);         /* should match the queue in ssh.c */
+        assert(globreq);         /* should match the queue in connection2.c */
         if (globreq->type == GLOBREQ_TCPIP_FORWARD) {
             if (type == SSH2_MSG_REQUEST_FAILURE) {
                 share_remove_forwarding(cs, globreq->fwd);
@@ -1289,7 +1289,8 @@ void share_got_pkt_from_server(ssh_sharing_connstate *cs, int type,
         break;
 
       default:
-        unreachable("This packet type should never have come from ssh.c");
+        unreachable("This packet type should never have come from "
+                    "connection2.c");
     }
 }
 
@@ -1356,12 +1357,12 @@ static void share_got_pkt_from_downstream(struct ssh_sharing_connstate *cs,
             host = mkstr(hostpl);
 
             /*
-             * See if we can allocate space in ssh.c's tree of remote
-             * port forwardings. If we can't, it's because another
-             * client sharing this connection has already allocated
-             * the identical port forwarding, so we take it on
-             * ourselves to manufacture a failure packet and send it
-             * back to downstream.
+             * See if we can allocate space in the connection layer's
+             * tree of remote port forwardings. If we can't, it's
+             * because another client sharing this connection has
+             * already allocated the identical port forwarding, so we
+             * take it on ourselves to manufacture a failure packet
+             * and send it back to downstream.
              */
             rpf = ssh_rportfwd_alloc(
                 cs->parent->cl, host, port, NULL, 0, 0, NULL, NULL, cs);
@@ -1430,8 +1431,8 @@ static void share_got_pkt_from_downstream(struct ssh_sharing_connstate *cs,
                 }
             } else {
                 /*
-                 * Tell ssh.c to stop sending us channel-opens for
-                 * this forwarding.
+                 * Tell the connection layer to stop sending us
+                 * channel-opens for this forwarding.
                  */
                 ssh_rportfwd_remove(cs->parent->cl, fwd->rpf);
 
@@ -1872,8 +1873,8 @@ void share_activate(ssh_sharing_state *sharestate,
                     const char *server_verstring)
 {
     /*
-     * Indication from ssh.c that we are now ready to begin serving
-     * any downstreams that have already connected to us.
+     * Indication from connection layer that we are now ready to begin
+     * serving any downstreams that have already connected to us.
      */
     struct ssh_sharing_connstate *cs;
     int i;

ssh/ssh.c

@@ -1246,7 +1246,7 @@ static int ssh_cfg_info(Backend *be)
 
 /*
  * Gross hack: pscp will try to start SFTP but fall back to scp1 if
- * that fails. This variable is the means by which scp.c can reach
+ * that fails. This variable is the means by which pscp.c can reach
  * into the SSH code and find out which one it got.
  */
 extern bool ssh_fallback_cmd(Backend *be)