/usr/bin/ld: cannot find -lpng
collect2: ld returned 1 exit status
make[2]: *** [libgnashbackend.la] Error 1
make[2]: Leaving directory `/home/lontra/Desktop/gnash-0.7.1/backend'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/lontra/Desktop/gnash-0.7.1'
make: *** [all] Error 2