Provide runtime version of wire_bsdio_impl2

This will allow adapters to take advantage of newer library versions

Change-Id: I7eb572c51ad99231b8ffa1d03dfee6e55ef9cfa9
Reviewed-on: http://review.couchbase.org/43701
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>