gdash: Prefix all metric names with 'MediaWiki.'

On tungsten, the new Graphite host, metrics generated by MediaWiki are
namespaced under 'MediaWiki', rather than being top-level names. This should be
merged after the CNAME record for graphite.wikimedia.org is updated.

Change-Id: If9a3810f3b16354a8d4a8d2cea7e50be28dfb277
Move sqstat (udp2log to carbon) to tungsten

tungsten is the new carbon box.

Change-Id: I7efc9cb41bee3d4f90d3bfc05bf491094e2bb230