[Change] Handle libpng dependancy a little better.

README

@@ -43,6 +43,7 @@ Dependencies:
 			-- libgl1-mesa-dri
 			-- libxml2
 			-- libfreetype6
+      -- libpng12-0
 
 		-- Source:
 			-- libsdl1.2-dev
@@ -51,6 +52,7 @@ Dependencies:
 			-- libgl1-mesa-dev
 			-- libxml2-dev
 			-- libfreetype6-dev
+      -- libpng12-dev
 
 
 Instructions:

bin/Makefile

@@ -28,8 +28,9 @@ CLUA := -I../lib/lua
 CSDL := $(shell sdl-config --cflags)
 CXML := $(shell xml2-config --cflags)
 CTTF := $(shell freetype-config --cflags)
+CPNG := $(shell pkg-config libpng --cflags)
 CGL  :=
-CFLAGS := $(CLUA) $(CSDL) $(CXML) $(CTTF) $(CGL) $(VERSION) -D$(OS)
+CFLAGS := $(CLUA) $(CSDL) $(CXML) $(CTTF) $(CPNG) $(CGL) $(VERSION) -D$(OS)
 
 # OS Stuff.
 ifeq ($(OS),LINUX)
@@ -60,9 +61,9 @@ LDLUA := ../lib/lua/liblua.a
 LDSDL := $(shell sdl-config --libs) -lSDL_image -lSDL_mixer
 LDXML := $(shell xml2-config --libs)
 LDTTF := $(shell freetype-config --libs)
+CPNG 	:= $(shell pkg-config libpng --libs)
 LDGL	:= -lGL
-LDPNG   := -lpng
-LDFLAGS := -lm $(LDLUA) $(LDSDL) $(LDXML) $(LDTTF) $(LDGL) $(LDPNG)
+LDFLAGS := -lm $(LDLUA) $(LDSDL) $(LDXML) $(LDTTF) $(CPNG) $(LDGL) $(LDPNG)
 
 # This is just for gstat to run some analysis on performance.
 ifdef DEBUG