Easily inject code into OS X apps

You're gonna get some hop-ons.

This code is rough, but workable. I'm not an expert in mach_inject, XPC, or launchd, so this may be buggy. But it's at least a start.

Here's a rough outline of the steps to use HopOn:

0. Add HopOn as a submodule

1. Bootstrap HopOn: script/bootstrap.

2. Add HopOn.xcodeproj to your project or workspace.

3. Add HopOn.framework and com.diephouse.matt.HopOn-Injector to your project's dependencies.

4. Add a build phase to copy HopOn.framework into your app's Frameworks directory.

5. Add a build phase to copy com.diephouse.matt.HopOn-Injector to Contents/Library/LaunchServices in the Wrapper destination.

6. Set the Runpath Search Paths to @loader_path/../Frameworks in your app's build settings.

7. Add a file called HOPON_HOST_IDENTIFIER in a directory above the HopOn directory that contains the identifier of your app. This is needed for the launch service's permissions.

8. Add a SMPrivilegedExecutables dictionary to your app's info.plist with the key com.diephouse.matt.HopOn-Identifier and the value identifier "com.diephouse.matt.HopOn-Identifier".

9. Create a "Bundle" target in your app to host the injected code. You can add classes and use +load or a function like this:

attribute((constructor)) void load() { ... }

0. Copy your bundle into your app in a build phase.

0. In your app, call `+[HopOn injectBundleAtURL: intoApplication:];` to inject your bundle into a target app.

## License
Available under the MIT License.