Owfs update

I hope I did this correctly.  
There should be only 2 files.
I need a few people to test the update Owfs_Item before merging to the master branch.

The new Owfs_Item uses a Socket_Item to connect to the owserver instead of a direct socket connection.  This has the advantage of avoiding any stalls in the MH main loop.

Another major change is the fact the "state" information is now properly stored in the base Generic_Item.  This wasn't the case before.

Another major change is the state for PIO, LATCH, and SENSE has changed from 0/1 to ON/OFF.  

If using a raw Owfs_Item, doing a ->get( ) will not return the state, but instead request a fetch of the state.  The updated state will be available by ->state( ).