Revert "Revert to using fpp instead of direct sockets for now."

This reverts commit 624ffe25bbc195429b32f719deb713904c2f9a8e.

I have now tested that this works properly on a PI, so we can move
forward with these changes.

Conflicts:
	www/fppxml.php

Conflict notes:
  The change for cleaning up the status XML code duplication caused
  a couple easily-resolved conflicts.