JsCoreEngineWrapper
-------------------
Simple singleton iOS class that wraps a JavascriptCore library to process javascript in the background thread

Installation
------------
1. Import all the files into your project
2. Go to build phases and add the following libraries:
   - libstdc++.dylib
   - libicucore.dylib
   - libiOSJavaScriptCore.a
3. import "JsCoreEngineWrapper.h"

Usage
-----

1. Implement delegate methods to get the callback

eg.
- (void)JsCoreEvalResultsDidLoad:(NSString *)result {
  NSLog(@"results: %@", result);
}

2. Anywhere in your class, invoke javascript

eg.
[JsCoreEngineWrapper instance].evalJsString("...")];

3. Get the result in the delegate method and there you have it! Javascript in the background thread.