Implement campaign statistics reports on stats.wesnoth.org

by Gregory Shikhman for Battle for Wesnoth

Wesnoth currently has a basic website for viewing campaign completion information at http://stats.wesnoth.org, but it is very basic. I will create a site that allows users to view campaign info with filters (ex. view all wins on Heir to the Throne on OSX). The system must quickly parse 100k+ data entries and generate graphs from them. There must also be good control over presentation of data (date range, side by side comparison for certain filters).