merge LocalArray and LocalArrayRead, rename to LocalVector

[stevengj]

We could probably have a single type LocalArray{T,readonly} where readonly is true or false

Also, in keeping with Julia nomenclature, it should probably be called LocalVector since it is a subtype of AbstractVector (or DenseVector ala #76).

[JaredCrean2]

I like the name change. The problem with making readonly a static parameter is I don't see a way to doing it that doesn't lead to the #59 or requires excessive information. We could either have the outer constructor

LocalVector{T}(v::Vec; readonly=false)
  return LocalVector{t, readonly}(...args...)

which is type unstable, or the inner constructor:

type LocalVector{T, readonly}
  ... fields...
  function LocalVector(x::Vec)
     return new(...args...)
  end
end

which requires specify the element type T again, even though it is already contained in x.

[stevengj]

We could have type-stable outer constructors LocalVector{T}(v::Vec{T}) = LocalVector{T,false}(...) and LocalVector_readonly{T}(v::Vec{T}) = LocalVector{T,true}(...), though I'm not completely happy with the latter name.

[JaredCrean2]

I'm not happy with the latter name either, but I can't think of anything better, so let's go with it for now.

[JaredCrean2]

This was closed by #80