Added OCInject v0.3.0.

OCInject is a fast and simple dependency injection framework which does not steal constructors from  developers.

- Fast and small.
- Really easy to use.
- Does not steal `[[Class alloc]initWithSomeArgs]` from you.
- Does not manage your application object graph.
- Injects dependencies everywhere via `OCInject(Class)` and `OCInjectProtocol(protocol)` functions.
- Provides an optional category method `[NSObject inject]` equivalent to `OCInject(class)`.
- Requires almost zero configuration because of runtime bindings.
- Transparently integrates into tests/mocks.