add experimental support to scan epg in background using different tuner,

when enabled in menu - activated by next channel switch,
scanning epg for channels (transponders) in current bouquet (channels list)


Origin commit data
------------------
Commit: 8e6202071e
Author: [CST] Focus <focus.cst@gmail.com>
Date: 2013-06-12 (Wed, 12 Jun 2013)

src/driver/scanepg.h

@@ -0,0 +1,45 @@
+/*
+        Copyright (C) 2013 CoolStream International Ltd
+
+        License: GPLv2
+
+        This program is free software; you can redistribute it and/or modify
+        it under the terms of the GNU General Public License 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.
+*/
+
+#ifndef __SCAN_EPG__
+#define __SCAN_EPG__
+
+#include <zapit/zapit.h>
+
+typedef std::map<transponder_id_t, t_channel_id> eit_scanmap_t;
+typedef std::pair<transponder_id_t, t_channel_id> eit_scanmap_pair_t;
+typedef eit_scanmap_t::iterator eit_scanmap_iterator_t;
+
+class CEpgScan
+{
+	private:
+		int current_bnum;
+		eit_scanmap_t scanmap;
+		std::set<transponder_id_t> scanned;
+
+		CEpgScan();
+	public:
+		~CEpgScan();
+		static CEpgScan * getInstance();
+
+		void handleMsg(const neutrino_msg_t _msg, neutrino_msg_data_t data);
+		void Clear();
+};
+
+#endif