feature(util) add checkType

lib/util.js

@@ -144,6 +144,22 @@
                 }
         };
         
+        /**
+         * Check is type of arg with name is equal to type
+         * 
+         * @param name
+         * @param arg
+         * @param type
+         */
+        this.checkType          = function(name, arg, type) {
+            var is = Util.getType(arg) === type;
+            
+            if (!is)
+                throw(Error(name + ' should be ' + type));
+            
+            return this;
+        };
+        
         /**
          * Check is Properties exists and they are true if neaded
          *