Support for horizontal dragging

[dev-bre]

Any idea how to update this layout to support horizontal dragging as well? It could be really useful in case of tablets where the screen goes more horizontally than vertically.

[justasm]

I agree. See #10, #12 and #20 for previous discussions regarding this issue.

Also check out the work of @cmcneil and @meesec in their respective forks for some inspiration.

https://github.com/cmcneil/DragLinearLayout
https://github.com/meesec/DragLinearLayout