Added commands to access player stats.

Loosely based on code from jcao219. New commands are "player", "p", "mystats", "me". The commands access existing stats stored in the game database (data.sqlite3).
Added game stats to database and "gamestats" command.

Added a game stats table to game DB to store wolf/village wins for
each game size. Added "gamestats" command to display stored stats.
Fix for multi-word roles.

Also added help definition for "mystats" command.
Changed behaviour of "gamestats" command.

"gamestats" without a parameter will list game totals for all game
sizes. The role parameter for player stats commands is now case
insensitive.
Fix for secure SQL operations.

Removed Python string operations from SQL operations.
Updated stats text. Player stats command checks for account.

Updated game text for stats commands. Fixed error with "mystats" help
string. Added additional check in player stats commands to find the
associated account before attempting to retrieve stats.
Added additional limits for "gamestats" parameters.

Added check to make sure the parameter is an integer between 4 and
var.MAX_PLAYERS.
Merge pull request #20 from brrr2/stats-pr

Adds player and game stats commands