allow to hide config items from the ui and allow to change config values in the init function

lib/config/GWConfig.cpp

@@ -114,6 +114,16 @@ int GwConfigHandler::getInt(const String name,int defaultv) const{
     if (!i) return defaultv;
     return i->asInt();
 }
+void GwConfigHandler::stopChanges(){
+    allowChanges=false;
+}
+bool GwConfigHandler::setValue(String name,String value){
+    if (! allowChanges) return false;
+    GwConfigInterface *i=getConfigItem(name,false);
+    if (!i) return false;
+    i->value=value;
+    return true;
+}
 
 void GwNmeaFilter::handleToken(String token, int index){
     switch(index){

lib/config/GWConfig.h

@@ -14,11 +14,13 @@ class GwConfigHandler: public GwConfigDefinitions{
         GwLog *logger;
         typedef std::map<String,String> StringMap;
         StringMap changedValues;
+        boolean allowChanges=true;
     public:
         public:
         GwConfigHandler(GwLog *logger);
         bool loadConfig();
         bool saveConfig();
+        void stopChanges();
         bool updateValue(String name, String value);
         bool reset(bool save);
         String toString() const;
@@ -27,6 +29,12 @@ class GwConfigHandler: public GwConfigDefinitions{
         bool getBool(const String name,bool defaultv=false) const ;
         int getInt(const String name,int defaultv=0) const;
         GwConfigInterface * getConfigItem(const String name, bool dummy=false) const;
+        /**
+         * change the value of a config item
+         * will become a noop after stopChanges has been called 
+         * !use with care! no checks of the value
+         */
+        bool setValue(String name, String value);
     private:
 };
 #endif