Keen Modding Live - More info on player page

Previously, Keen Modding Live had no way to get from a player page to the level's information page. So today I populated the player page with some useful information: level description, version comment, level owner, version author (if different than the level owner), and version creation time. While I was at it, I made the player page return an HTTP error and bail out if the level or version ID can't be found instead of spewing dozens of PHP errors. The link that goes back to the level information page reads "see other versions of this level," so I suppose the next thing to do is actually render the version tree on the level page.