This patch introduces IPC::Connection which becomes the new base class
of ClientConnection and ServerConnection. Most of the functionality
has been hoisted up to the base class since almost all of it is useful
on both sides.
This gives us the ability to send synchronous messages in both
directions, which is needed for the WebContent server process.
Unlike other servers, WebContent does not mind blocking on a response
from its client.
You can now mark String message parameters with the [UTF8] attribute.
This will cause the generated decoder to perform UTF-8 validation and
reject the message if the given parameter is not a valid UTF-8 string.
This frees up the receiving side from having to do this validation at
a higher level.
It didn't feel right to have a "DHCPClient" in a "Servers" directory.
Rename this to Services to better reflect the type of programs we'll
be putting in there.
