Enable PostEdit on bn, br, ca, cs, et, ka and zh wikis

Change-Id: Ia2665c4feae1586bdc0f6824e631e3a1f55089fa
$wgNavigationTimingSamplingFactor: 10000 => 5000.

The current sampling factor of 10,000 produces about 2.75 events per second.
This seems consistent with cluster-wide request stats, given that not all
browsers implement the Navigation Timing API and are therefore excluded from
data collection.

Halving the sampling factor will double the rate of events to 5.5 / sec. This
will help generate adequate data from mobile alpha / beta.

Change-Id: Ibc2633f1ceef42cf3a5fa6a40252c14e5513956b
Merge "$wgNavigationTimingSamplingFactor: 10000 => 5000."
Merge "Enable PostEdit on bn, br, ca, cs, et, ka and zh wikis"