Inform about clients simulating too slowly / simulation lag

[elexis]

It is not rare that one player has a significantly worse computer, driver, too few memory or too many applications opened ("potato computer") and thus needs more than the intended 500ms to compute the next simulation turn.

The network connection maybe perfect, but if the CPU needs up to 1000ms to compute the next turn, players will be able to play for 500ms and then have to wait 500ms repeatedly until the game has ended or the slowest client left.

It should be communicated to the players why the game is not progressing with the intended gamespeed, which player is affected to which degree and whether there is a single client that may be much slower than all the others and might have to be kicked and spared from future games.

In particular attackers and trolls can and do trigger this kind of unreported lag purposefully by for example pausing without sending the pause network packet or by reducing the simulation rate through the JS interface.

Notice if players selected too much population, every player will be affected by simulation lag terribly. If there are too many lagwarnings shown simultaneously without a way for players or the host to fix it, the lagwarnings will not be read any further and are only bothersome. Due to the noise, more relevant network warnings (meanRTT, packet loss) may not receive the attention they need (network issues can be fixed during a game, simulation issues not really) and I have patch, you don't.