[LIBART] Cool demo, graphics bug

[Danny Holth <dholth stetson edu>]

Libartisans,

	Check out this image at http://galatea.setson.edu/~dholth/art.png
[it is about a megabyte, 1200x1200 pixels].  It was generated in 2:35 of
elapsed time on a dual 300mhz PII, from a postgres database.  The database
contains five counties worth of freely available US census TIGER data.
The map represents 81.7 deg. W to 80.85 deg. W and 28.4 deg N to 29.4 deg
N.  [Central Florida].

	Notice the graphics glitches.  What has gone wrong here?  I assume
it is because my points are too close together.  (I am linking with
libart_lgpl.so.2.2.0.)  I also wonder why it dosn't work well to e.g. put
all my lines of a certain color into an array and then make a single call
to stroke and art_rgb_svp_alpha, I get a lot of 'colinear' errors.

	Thanks, hope you enjoy the map (yes, the data allows you to fill
the lakes with a little more work.)

	- Daniel Holth