Xconq game setup changes

[Stan Shebs <shebs at shebs dot cnchost dot com>]

Hans and I have been tinkering with game setup options, and there's
various new stuff in CVS.

There is now a variant help string that game designers can add
right after the variant's symbol.  This is what gets displayed
at the bottom of the variant dialog when you roll the mouse
around it.  No more mystery options...

Also, it is now possible to specify which type of AI plays
the independent units, and even to play them yourself!  It
looks weird to me, and will be really weird for some games,
but Hans swears it's great fun, and now you get a chance to try
it out too!  You do this by noting that "Independents" shows
up as a side in the player setup dialog, clicking on it to
select, then manipulating with the buttons just like any
other side.

Stan