Move private APIs to private namespace

Fixes #2078

src/core/Expector.js

@@ -5,7 +5,7 @@ getJasmineRequireObj().Expector = function(j$) {
     };
     this.actual = options.actual;
     this.addExpectationResult = options.addExpectationResult || function() {};
-    this.filters = new j$.ExpectationFilterChain();
+    this.filters = new j$.private.ExpectationFilterChain();
   }
 
   Expector.prototype.instantiateMatcher = function(
@@ -39,7 +39,7 @@ getJasmineRequireObj().Expector = function(j$) {
           this.matchersUtil,
           args
         );
-      } else if (j$.isFunction_(result.message)) {
+      } else if (j$.private.isFunction(result.message)) {
         return result.message();
       } else {
         return result.message;