Show/hide the wikibase watchlist entries server side

(Requires I79811e9f3e7431e3403cf93674667d624d3d4db2)

patchset 8: fixed & improved selenium tests

Change-Id: I267a755a70cdc7d4937ab70364b34e73da780ef0
Merge "Show/hide the wikibase watchlist entries server side"