2020-02-20 Fred Gleason <fredg@paravelsystems.com>

* Added a 'FEEDS.AUDIENCE_METRICS' field to the database.
	* Incremented the database version to 316.
	* Added a 'Collect Audience Metrics' checkbox to the 'Feed'
	dialog in rdadmin(1).
	* Added an 'RDTransfer' base class.
	* Rebased 'RDDelete' to 'RDTransfer'.
	* Added 'sftp' support to 'RDDelete'.
	* Added 'file' support to 'RDDelete'.
	* Refactored RSS generation to occur in 'RDFeed'.
	* Added a 'delete_test' test harness.

lib/rdtransfer.cpp

@@ -0,0 +1,48 @@
+// rdtransfer.cpp
+//
+// Abstract base class for Rivendell remote data tranfer methods
+//
+//   (C) Copyright 2020 Fred Gleason <fredg@paravelsystems.com>
+//
+//   This program is free software; you can redistribute it and/or modify
+//   it under the terms of the GNU General Public License version 2 as
+//   published by the Free Software Foundation.
+//
+//   This program is distributed in the hope that it will be useful,
+//   but WITHOUT ANY WARRANTY; without even the implied warranty of
+//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//   GNU General Public License for more details.
+//
+//   You should have received a copy of the GNU General Public
+//   License along with this program; if not, write to the Free Software
+//   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+
+#include "rdtransfer.h"
+
+RDTransfer::RDTransfer(RDConfig *c,QObject *parent)
+  : QObject(parent)
+{
+  xfer_config=c;
+}
+
+
+bool RDTransfer::urlIsSupported(const QString &url)
+{
+  return urlIsSupported(QUrl(url));
+}
+
+
+bool RDTransfer::urlIsSupported(const QUrl &url)
+{
+  if(url.isRelative()||(!url.isValid())) {
+    return false;
+  }
+  return supportedSchemes().contains(url.scheme());
+}
+
+
+RDConfig *RDTransfer::config() const
+{
+  return xfer_config;
+}