0.3.0 - added caching to all requests. Changed authentication API. 

### Authentication changed

```
    +(void)SH_authenticateWithLoginViewControllerBlock:SHGameViewControllerBlock)theLoginViewControllerBlock
    didLoginBlock:(SHGameCompletionBlock)theLoginBlock
    didLogoutBlock:(SHGameCompletionBlock)theLogoutBlock
    withErrorBlock:(SHGameErrorBlock)theErrorBlock;
```
### Caching and requests

#### will write cache

```   
      GKTurnedBasedMatch SH_requestMatchesAndFriendsWithBlock:
      GKTurnedBasedMatch SH_requestPlayersWithBlock:
      GKLocalPlayer      SH_requestFriendsWithBlock:
```

#### will read cache
```
      GKTurnedBasedMatch  SH_requestMatchesWithBlock:
      GKTurnedBasedMatch  handleTurnEventForMatch:
      GKaTurnedBasedMatch handleMatchEnded:
```