Merging r6493 through r6517 from trunk to ogl-es branch

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/branches/ogl-es@6518 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/Irrlicht-gcc.cbp

@@ -864,6 +864,7 @@
 		<Unit filename="COpenGLCoreFeature.h" />
 		<Unit filename="COpenGLCoreRenderTarget.h" />
 		<Unit filename="COpenGLCoreTexture.h" />
+		<Unit filename="COpenGLCommon.h" />
 		<Unit filename="COpenGLDriver.cpp" />
 		<Unit filename="COpenGLDriver.h" />
 		<Unit filename="COpenGLExtensionHandler.cpp" />

source/Irrlicht/Irrlicht10.0.vcxproj

@@ -1164,7 +1164,6 @@
     <ClInclude Include="CZBuffer.h" />
     <ClInclude Include="ITriangleRenderer.h" />
     <ClInclude Include="IZBuffer.h" />
-    <ClInclude Include="resource.h" />
     <ClInclude Include="S2DVertex.h" />
     <ClInclude Include="SB3DStructs.h" />
     <ClInclude Include="CColorConverter.h" />

source/Irrlicht/Irrlicht10.0.vcxproj.filters

@@ -1269,7 +1269,6 @@
     <ClInclude Include="..\..\include\IAnimatedMeshMD3.h">
       <Filter>include\scene</Filter>
     </ClInclude>
-    <ClInclude Include="resource.h" />
     <ClInclude Include="CSceneLoaderIrr.h">
       <Filter>Irrlicht\scene\loaders</Filter>
     </ClInclude>

source/Irrlicht/libpng/pngstruct.h

@@ -27,7 +27,20 @@
    /* We must ensure that zlib uses 'const' in declarations. */
 #  define ZLIB_CONST
 #endif
-#include "zlib.h"
+
+/* Irrlicht change: 
+   Avoid that build-in png uses a different zlib than the rest of Irrlicht.
+   Note: This also would allow removing zlib from the include paths, which 
+   probably was done just to hide this bug. Anyway, it's less broken now 
+   than it was and the rest is up to Irrlicht 1.9.
+*/
+#include "IrrCompileConfig.h"
+#ifndef _IRR_USE_NON_SYSTEM_ZLIB_
+	#include <zlib.h> // use system lib
+#else
+	#include "../zlib/zlib.h"
+#endif
+
 #ifdef const
    /* zlib.h sometimes #defines const to nothing, undo this. */
 #  undef const