DotA multi region hosts added

• Added Asia (Singapore) and South America (Brazil) bots.
• You can now use !pub<region> or !priv<region> commands to use a specific regional bot. E.g.: !pubas to use asian hostbot, !pubsa to use South American.
  
• If you don’t specify any region, default is eu (Germany).
• 2 bots available in SA and AS; 4 in EU (concurrent lobbies).
• Added !regions command to list all available regions.
• Added !region lobby command to display hostbot’s region. Region is also printed in the lobby welcome message.
• !gopub and !gopriv command variants were removed to reduce unnecessary options doing the same thing.
• No matter what region you choose, all games count towards the single ladder.
• We advise to put region name in game name when hosting.