Summary:**Problem**: As seen in https://github.com/facebook/react-native/issues/5820, many devs are confused by the fact that the offline bundle is not generated when running against the simulator, even when running in the "Release" configuration which is supposed to mimic "production" scenarios.
This pull request is a small change that fixes https://github.com/facebook/react-native/issues/5820 by updating the `react-native-xcode.sh` shell script to still generate the ofline bundle during Release configuration. It also updates `AppDelegate.m` to better document this behaviour in the comments so as to avoid any surprises.
**Test plan**: This is a simple change, the two tests done were
1. In a new React Native project, verify that an offline build is not generated when running against the simulator in "Debug" configuration as per normal.
2. Change to a "Release" configuration via Product > Scheme > Edit Scheme in XCode, then verify that the project runs with the offline build generated.
![screen shot 2016-02
Closes https://github.com/facebook/react-native/pull/6119
Differential Revision: D2970755
Pulled By: javache
fb-gh-sync-id: 64f658512869c73aa19286ca1e3dc6e31b5ac617
shipit-source-id: 64f658512869c73aa19286ca1e3dc6e31b5ac617
Summary: public
We moved to using `new` instead of `alloc] init` but there was still some calls
left.
Reviewed By: javache
Differential Revision: D2604679
fb-gh-sync-id: ff7300ecbedb55dd5e93873592598810c9b87808
Geoffrey Goh
Tadeu Zagallo
Alex Kotliarskyi
Pieter De Baets
Pieter De Baets
Martin Konicek
Felix Oghină
