Rename StaticArray to AbstractStaticArray

[mohamed82008]

The name StaticArray seems confusing with its subtype SArray. I think it would be clearer if StaticArray is named to AbstractStaticArray then when I see SVector, SMatrix and SArray I would unconfusingly think they are probably concrete subtypes, of AbstractStaticArray.

[c42f]

TBH I don't think we're going to do this for StaticArrays-1.0. It's not a bad idea in principle, just rather breaking.