Fixed master server spam by excluding servers that don't ping back

[Mailaender]

I first thought about inventing a new ServerState.NotResponding to get rid of the [down] prefix, but than why should we even list those especially when it is a good opportunity to finally fix #5.

[ihptru]

what is this? this does not fix either #5 or proposed #29
this only updates games.txt file with counter, just on different condition.

[Mailaender]

I updated this a couple of times. Tried to create a test area at http://master.openra.net/staging/ but this is tricky to debug. Not sure if this really works how I want.

[ihptru]

Looks good, the only thing I noticed about OpenRA Server, is that it will dequeue "Master Server communication established" and will keep pinging Master server, endlessly getting 'server ... does not respond' in background. Maybe add some error code to response of master server and parse it on OpenRA side to stop pinging it?

[ihptru]

it's 👍 though, for current version. Also want to see how well it will work in production.

With current realization, there will be no more games in server browser with closed ports. And for server hosters with not forwarded ports, message "Master server communication established" and no evidence of their server online, there will be a definite answer to forward ports.

[ihptru]

Just basic information which can be useful in future (following the result behavior after merging it, and the next PR following after it (#30)):

Started games with closed ports are still advertised. (Appeared that default socket test function in php fails for any started OpenRA game with closed or opened ports).

Also, with this PR, servers with not forwarded ports automatically does NOT added to tables: started, finished and map_stats