Added hitcount Transform function.

src/app/services/graphite/gfunc.js

@@ -192,6 +192,13 @@ function (_) {
     category: categories.Transform,
   });
 
+  addFuncDef({
+    name: 'hitcount',
+    category: categories.Transform,
+    params: [ { name: "interval", type: "string" }],
+    defaultParams: ['10s']
+  });
+
   addFuncDef({
     name: 'averageAbove',
     category: categories.Filter,