Use hasOwnProperty with property names from user

[juhoz1024]

Hi,

I have a corner case with a route called "watch" and Firefox.

Here's the relevant code from Restangular 1.4.0:

config.transformElem = function(elem, isCollection, route, Restangular, force) {
    if (!force && !config.transformLocalElements && !elem[config.restangularFields.fromServer]) {
      return elem;
    }
    var typeTransformers = config.transformers[route];
    var changedElem = elem;
    if (typeTransformers) {
        _.each(typeTransformers, function(transformer) {
           changedElem = transformer(isCollection, changedElem);
        });
    }
    return config.onElemRestangularized(changedElem,
      isCollection, route, Restangular);
};

Besides formatting changes, the code is the same in 1.5.1.

The exact line that's the source of the issue:

    var typeTransformers = config.transformers[route];

What exactly goes wrong:

1. config.transformers is empty, i.e., {}
2. route is "watch"
3. config.transformers[route] should be undefined
4. instead, it's picking up Object.prototype.watch

Changing the line to:

    var typeTransformers = config.hasOwnProperty(route) && config.transformers[route];

would fix the problem.

Similar checks should be added everywhere the property name comes from outside Restangular.