Allow for different/custom LayoutManagers

[gtcompscientist]

As a user, it would be helpful to be able to pass in a custom *LayoutManager to the bind function.

[radoyankov]

There is a layoutManager() function which does this.

[gtcompscientist]

Doesn't it make far more sense to include this as an override in the setup?

[radoyankov]

Default startup takes a linear layout, which is the most commonly used one. If I make it a parameter in the bind function it would have to be optional, and I want to avoid adding optional parameters to the function to keep it simple.

[gtcompscientist]

fun <T> RecyclerView.bind(items: List<T>,
                          @LayoutRes singleLayout: Int = 0,
                          manager: RecyclerView.LayoutManager = LinearLayoutManager(context),
                          singleBind: (View.(item: T) -> Unit))
        : FastListAdapter<T> {
    layoutManager = manager
    return FastListAdapter(
            items,
            this
    ).map(singleLayout, { true }, singleBind)
}

Use:
recyclerView.bind(items, *LayoutManager()) { ... }

This seems a lot more intuitive to use than adding a trailing .layoutManager() call.

*Also allows you to only have a single "bind" function.