Update to use the new DatTCP, rename server to server old

This updates Sanford to work with the latest DatTCP but also
renames server to server old. This is done to make room for
reworking the server without breaking sanfords full functionality.
Until we are ready to switch to the new server logic, the old
logic can continue to be function. This switches to using the
new DatTCP with leaving the server logic as unchanged as possible.
This doesn't change any functionality, just switches out to the
new DatTCP and renames the server.
Merge pull request #112 from redding/jcr-new-dat-tcp

Update to use the new DatTCP, rename server to server old
Add new `Server` DSL

This adds a new `Server` and the DSL for configuring it. This is
part of the effort to rework the `Server` and startup process for
Sanford. This moves most of the `Host` configuration over to the
`Server` and the DSL for configuring it as well. This also moves
the template source configuration to the `Server` from the
global Sanford config. Both the `Host` and `Config` will be
removed later in favor of the new `Server`.