Move misc::graphite::navtiming into webperf role

'navtiming' is a Python daemon that processes incoming NavigationTiming events
and generates Ganglia metric data. This patch extricates it from misc::graphite
and moves it into the webperf module instead.

Change-Id: I26c37769b132c15f994e8137719dd2db11ad82af
Merge "Move misc::graphite::navtiming into webperf role" into production