Filter selection "active"

[marianet]

trafficstars

In a Dashboard "By name", "By date", "Showcase" filters should be active when someone clicks on them. If click on By Name, then the buttom gets background white, letters black and stay like this. In showcase, we should add a tooltip that said something like "Hackathon organizers use 'Showcase' to select projects that really happened in the event". (not sure about the text, but it should explain what's Showcase doing.)