Add log if filter field doesn't match anything

SabreTools.Filtering/Filter.cs

@@ -33,12 +33,6 @@ namespace SabreTools.Filtering
 
         #region Filter Population
 
-        /// <summary>
-        /// Populate the filters object using a set of key:value filters
-        /// </summary>
-        /// <param name="filters">List of key:value where ~key/!key is negated</param>
-        public abstract void PopulateFromList(List<string> filters);
-
         /// <summary>
         /// Split the parts of a filter statement
         /// </summary>