Fix links to PS rooms
Fix links to PS rooms

Clicking links to PS rooms can be pretty unreliable in terms of whether
and where they open. This commit uses a global click handler, to make
sure that any and every link to PS rooms, including links in the News,
will open in the current PS window.

You can always right-click and Open in New Tab, of course.

Zarel/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,panpawn/Gold-Client,sirDonovan/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,panpawn/Gold-Client,sirDonovan/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,panpawn/Gold-Client,Zarel/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client