[Freeciv-Dev] (PR#12888) testing rulesets integrity

["Peter Schaefer" <peter.schaefer@xxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12888 >

starting the client to test a ruleset is a pain, since the game
requires at least one client to start, OR using the gui, the server
output is not copied

better would be:
- make commandline options that make the server read a ruleset and
other data before game starts solely for the purpose of testing
- allow setting minplayers to zero
- make server give some info to clients about why the server aborts