minor updates

@joecarney Hi, thank you very much for this useful library.

I've made some minor fixes for JCGridMenu. So I would like you to take a look at this.

1. Added `.gitignore` and removed unnecessary `.DS_Store` files.
2. Changed enum `UITextAlignment` to enum `NSTextAlignment`.
    - enum `UITextAlignment` is deprecated in iOS 6.
3. Changed enum `UIViewAnimationCurve` to enum `UIViewAnimationOptions`.
    - it seems that the `options` parameter type of `UIView`'s `animateWithDuration:delay:options:animations:completion:` is `UIViewAnimationOptions`.

Regarding 2 & 3, under present implementation, compile time warnings come out when the option "Implicit Enum Conversions" in "Build setting" is set to YES. I think this is the default setting of the latest XCode project. So it may be problematic to migrate JCGridMenu with existing project.

Thanks in advance for your support!