gui/update.cpp: add function to check first url for image update;

check update version and timestamp to notify user about updates


Origin commit data
------------------
Commit: a755074c0e
Author: [CST] Focus <focus.cst@gmail.com>
Date: 2014-10-20 (Mon, 20 Oct 2014)

src/gui/update.h

@@ -53,8 +53,8 @@ class CFlashUpdate : public CProgressWindow
 	std::string sysfs;
 	char	fileType;
 	int 	width;
+	bool	notify;
 	
-	std::string installedVersion;
 	std::string newVersion;
 	int	menu_ret;
 	int softupdate_mode;
@@ -66,6 +66,8 @@ class CFlashUpdate : public CProgressWindow
  public:
 	CFlashUpdate();
 	int exec( CMenuTarget* parent, const std::string & actionKey );
+	bool checkOnlineVersion();
+	void enableNotify(bool enable) { notify = enable; }
 
 };