[Freeciv-Dev] (PR#11851) Hack request should verify userid in addition to random string

["Ed Overton" <edoverton@xxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=11851 >

I've verified patch.hack_elev_envvar_check.txt on a windows gtk2 build.
 As a reminder, this patch uses an environment variable set in the
client, which is passed to the invoked server.  When a hack request is
made, the server checks the environment variable for a match.  If the
hack request is the first one with a match, then hack control is
granted.  The idea is that the environment variable gives a reassurance
that the hack request is coming from the client process that actually
launched the server.

Ed