Timeout handling

If NS2Stats doesn't respond after 5 seconds, revert to random sorting.
Ensure team difference is no greater than 1

May break immunity in low player counts, but it's the price to pay for
evenly spread teams. Immunity is generally a bad idea anyway.
Mapvote changes

- Fixed RTV votes that had no votes cycling the map if the next map vote
was set to be at the end of the map.
- Added "DontExtend" option to the config, lets you define maps that
should never be extended, ignoring other extension options.
- Added the sh_forcemapvote command, which will force a map vote if
possible.
Merge pull request #108 from Person8880/develop

Vote random and map vote improvements