PictureGame: version 3.0, which mostly works w/ current stable MW.

Right now the only obvious bug that I'm aware of is that the "Reupload"
feature is broken (JS issue).
I.e. after you upload a picture (via the form embedded on the picture game
creation page), the image shows up together with the "Reupload" link;
clicking on the "Reupload" link brings up the AJAX spinner image but the
upload form won't show up again.

Change-Id: I5031a2fec31a214e26d7d83f7c4048084e7e917f