Better exception error messages for mid-air edit collision

sources/MVCFramework.RESTAdapter.pas

@@ -272,7 +272,7 @@ procedure TRESTAdapter<T>.DoInvoke(aMethod: TRttiMethod; const aArgs: TArray<TVa
       lResp := fRESTClient.Head(lURL);
     else
     begin
-      raise Exception.Create('Error Message');
+      raise Exception.Create('Invalid HTTP method');
     end;
   end;
 

sources/MVCFramework.pas

@@ -3984,7 +3984,7 @@ procedure TMVCController.CheckIfMatch(const Data: String);
 
   if lReqETag <> GetSHA1HashFromString(Data) then
   begin
-    raise EMVCException.Create(HTTP_STATUS.PreconditionFailed, 'mid-air collisions detected, cannot update or delete resource.');
+    raise EMVCException.Create(HTTP_STATUS.PreconditionFailed, 'mid-air collisions detected (invalid "if-match" value), cannot update or delete resource.');
   end;
 end;