Janic Duplessis eae4fe810f Improve YellowBox output format
Summary:
YellowBox currently assumes the first arg is a printf like format string, this adds support for any arguments so it works more like console in the browser. This also adds `stringifySafe` to format arguments when using printf style.

The main annoyance that this fixes is when trying to log a single object it will currently print [object Object] instead of the fully stringified version.

**Test plan**

Tested a bunch of different log combinations.

```js
console.warn({test: 'a'}); // {"test":"a"} (was [object Object] before this patch)
console.warn('test %s %s', 1, {}); // test 1 {}
console.warn('test %s', 1, {}); // test 1 {}
console.warn({}, {}, {}, {}); // {} {} {} {}
```
Closes https://github.com/facebook/react-native/pull/16132

Differential Revision: D5973125

Pulled By: yungsters

fbshipit-source-id: fc17105a79473a11c9b1c4728d435fc54fb094bb
2017-10-04 00:00:36 -07:00
..
2017-09-26 23:45:48 -07:00
2017-10-04 00:00:36 -07:00