updated setValidValues() to return pointer to self

Allows for chaining methods.

src/HomeSpan.cpp

@@ -1726,7 +1726,7 @@ unsigned long SpanCharacteristic::timeVal(){
 
 ///////////////////////////////
 
-void SpanCharacteristic::setValidValues(int n, ...){
+SpanCharacteristic *SpanCharacteristic::setValidValues(int n, ...){
   char c[256];
   String *s = new String("[");
   va_list vl;
@@ -1756,6 +1756,7 @@ void SpanCharacteristic::setValidValues(int n, ...){
   }
 
   homeSpan.configLog+=c;
+  return(this);
 }
 
 ///////////////////////////////

src/HomeSpan.h

@@ -275,7 +275,8 @@ struct SpanCharacteristic{
   
   boolean updated(){return(isUpdated);}           // returns isUpdated
   unsigned long timeVal();                        // returns time elapsed (in millis) since value was last updated
-  void setValidValues(int n, ...);                // sets a list of 'n' valid values allowed for a Characteristic.  Only applicable if format=uint8
+  
+  SpanCharacteristic *setValidValues(int n, ...);   // sets a list of 'n' valid values allowed for a Characteristic and returns pointer to self.  Only applicable if format=uint8
     
   String uvPrint(UVal &u){
     char c[64];