Include statistics panel on the left side of the main page

The main page has been augmented and now has a statistics panel containing a logout link, a greeting, and a form that the user can use to choose a game (by ID and round). The panel is currently unstyled.

- Included a side panel containing the stats, greetings, etc. which is vertically fixed on the screen.
- Allowed user to specify game ID and round using a form (instead of having to specify the same via the URL).
- Included a link to the logout page.
- Added a greeting to the current user on the stats panel, along with a sentence showing the current game ID and round being played.
- Added jQuery 1.10.2 in JS files.
- Made sure that PHP error is not thrown when the user accidentally specifies an invalid round or game ID (either through the form or the URL).