This also appears to fix crashes when running ReactTests with Chrome debugging enabled!
The crash when tests failed was due to JavaScriptCore trying to create a backtrace with the native call stack.
The test structure is now provided by a JS API, that is used by all things that run tests. Also, the tests can be run manually by tapping a button in the ReactTests app.
The deleteTestFiles() function is now added to the Realm object, so that it's easy for the RPC module to handle this as well. We can only do this in testing environments in the future.
