Development code for Sockets provider

- This is an incremental devel code for Sockets provider.

Please take a look at the verbs provider for how it handles sread with a threshold condition.  The threshold is a minimum of what the user specified and the number of entries that can actually be returned. We can pull completions off and copy them into the user's buffer as completions occur, until we hit the count.  This would avoid checking list_length repeatedly and does a better job of overlapping the reporting of the completion data with waiting for the last one to occur.