pull in png deps

http://bugs.gentoo.org/194958

--- Makefile.in
+++ Makefile.in
@@ -2,7 +2,7 @@
 CXX = @CXX@
 LD = $(CXX)
 LDFLAGS = @LDFLAGS@
-LDLIBS = $(shell sdl-config --libs) $(shell xml2-config --libs) -lSDL_image -lSDL_ttf -lm -lxml2 -rdynamic -ljpeg -ldl
+LDLIBS = $(shell sdl-config --libs) $(shell xml2-config --libs) -lSDL_image -lSDL_ttf -lm -lxml2 -ljpeg -ldl $(shell libpng-config --libs)
 PROG = SDLcam
 
 prefix=@prefix@
@@ -10,7 +10,7 @@
 
 CPPFLAGS = @CPPFLAGS@ -DMMX -DTIMER -DPROG_VERSION=\"0.8.1\" -DDATADIR="$(datadir)/SDLcam"
 
-MMXFLAGS =     -Wshadow -Wall $(shell sdl-config --cflags) $(shell xml2-config --cflags)
+MMXFLAGS =     -Wshadow -Wall $(shell sdl-config --cflags) $(shell xml2-config --cflags) $(shell libpng-config --cflags)
 CFLAGS = @CFLAGS@ $(MMXFLAGS) -Wstrict-prototypes
 CXXFLAGS = @CXXFLAGS@ $(MMXFLAGS)