See #713

This PR adds 3rd param TF2_IgnitePlayer to allow set duration of fire, while default value kept as 10.0 so older plugins should not break.

However when i tested this, i found out fire duration is capped to 10.0 seconds, even when tempted to set higher than 10. I believe this is valve's shitty fix on infinite fire duration from some weapons, which is really unfortunate. May still be helpful to some plugins when setting fire less than 10 seconds.

Example code when testing this, setting yourself on fire with duration.

#include <sourcemod>
#include <tf2>

public void OnPluginStart()
{
	RegConsoleCmd("sm_fire", Command_Fire);
}

public Action Command_Fire(int iClient, int iArgs)
{
	if (GetCmdArgs() == 0)
	{
		TF2_IgnitePlayer(iClient, iClient);
	}
	else
	{
		char sBuffer[4];
		GetCmdArg(1, sBuffer, sizeof(sBuffer));
		float flDuration = StringToFloat(sBuffer);
		TF2_IgnitePlayer(iClient, iClient, flDuration);
	}
	return Plugin_Handled;
}