Remove redundant brackets around NSNumber literals.
Merge pull request #88 from DaleJefferson/master

Remove redundant brackets around NSNumber literals.
Removing warnings in the test project.
Replace FCModelDatabaseQueueOperation with NSBlockOperation

NSBlockOperation offers the same functionality as
FCModelDatabaseQueueOperation. Less code is happier code!
Add database queue method to run blocks asynchronously

I find myself using a pattern like this to prevent the database
blocking my main thread:

```obj-c
FCModelDatabaseQueue *databaseQueue = …
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT
, 0), ^{
    [databaseQueue inDatabase:^(FMDatabase *database) {
        // queries & updates

      [[NSOperationQueue mainQueue] addOperationWithBlock:^{
          // update the UI
      }];
    }];
});
```

This is a little wasteful though, the global queue's worker thread is
now blocked waiting for the database queue's worker thread to return
control.

With an async method to `FCModelDatabaseQueue` the same example looks
like this:

```obj-c
    FCModelDatabaseQueue *databaseQueue = …
    [databaseQueue inDatabaseAsync:^(FMDatabase *database) {
        // queries & updates

        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            // update the UI
        }];
    }];
```
Merge pull request #90 from randomsequence/master

Replace FCModelDatabaseQueueOperation with NSBlockOperation, add async block call