Graphic Links patch

[John S. Skogtvedt]

Doesn't seem to compile. Ran svn up (at r1724), cleaned out my config,
did make clean and make, and got the following error when it ran the
links configure script:

checking for libpng >= 1.0.0... yes
checking LIBPNG_CFLAGS... -I/usr/include/libpng12
checking LIBPNG_LIBS... -lpng12
checking for png.h... yes
checking for libpng/png.h... no
checking for png_create_info_struct in -lpng... no
configure: error: You need libpng to compile Links in graphics mode
make[2]: *** [.configured] Fejl 1
make[2]: Forlader katalog '/home/jss/dslinux/user/links'
make[1]: *** [all] Fejl 2
make[1]: Forlader katalog '/home/jss/dslinux/user'
make: *** [subdirs] Fejl 1