Add logarithmic scale function

src/app/services/graphite/gfunc.js

@@ -232,6 +232,14 @@ function (_) {
     defaultParams: ['10s']
   });
 
+  addFuncDef({
+    name: 'log',
+    category: categories.Transform,
+    params: [ { name: "base", type: "int" }],
+    defaultParams: ['10']
+  });
+
+
   addFuncDef({
     name: 'averageAbove',
     category: categories.Filter,