[Bug-gnubg] New feature: direction arrow

[Holger]

Hi all,

After fiddling around for quite some time I've added a new feature to the 
GUI that should be rather visible when you start a new match. For the user 
there isn't much to explain. I hope you just like it. (In case somebody 
doesn't, should it be an option?)

The arrow is a vector graphic and gets drawn anti-aliased.

For the impatient (who can't wait for an update from Nardy or Øystein) 
there is an executable and a few necessary library files available at: 
http://storm.prohosting.com/gnubg/ . Some of the libraries I use have 
different versions from those of Nardy or Øystein. Unpack everything into 
your installation folder of GNUbg. (I hope to have uploaded everything 
well. Please mail me if there are problems.)

For those compiling themselves there are a few things to consider:

GNUbg depends now on LibArt. If you don't have the library it stays like it 
was before, you simply don't get any arrow.
For Windows LibArt is available on 
http://sourceforge.net/project/showfiles.php?group_id=23617 and 
http://sourceforge.net/project/showfiles.php?group_id=7382 . I've opted for 
the first one, because it has a newer date and the project seems to be more 
active.
In config.h you need #define HAVE_LIBART 1. And GNUbg needs to be linked 
with -lart_lgpl . I'm not sure whether the library has the same ending 
under *nix.

Could someone please adjust the automake stuff accordingly? I've put the 
libart macro into m4 already. But I suppose in some config.* it should be 
added. If you don't mind to explain what's necessary, I'd also like to 
learn a thing or two.

And finally, if anybody likes to make a nicer arrow: Please provide me with 
B-spline coordinates in the area of [0,10]. I'm thinking e.g. of a bent 
arrow and/or of the blended result of several objects (for a highlight spot 
or the like).

Regards,

        Holger