Sorted Containers

Added sorted containers to DataStructures, testing, and documentation.
Replaced README.md with README.rst
Yes, that is correct.  If you look at the `sort` code, `Forward` ordering is provided as a default, so the user doesn't have to specify it, and a separate `rev=true` keyword argument creates a `Reverse` ordering.  These two are assumed to be the most common, but others exist for various purposes.