Easy stats export

As of the latest version (2015.01.31.658), you can go to Tools > Export Stats within a league and export either player average stats or individual game stats. The exported file is in CSV format, which means you can easily view it in Excel or any other spreadsheet software if you want to more deeply analyze the stats in one of your leagues.

I know it's missing a couple things now (playoff stats, team stats, shot locations, ...), but I want to make sure the core feature works well before implementing all of those.