Avoid relying on max() from windows.h

Unfortunately, windows.h breaks the standard library because it
defines max() as a macro by default.

To fix this, add NOMINMAX (and WIN32_LEAN_AND_MEAN for good measure) to
the compile options. Ideally, this would be set on a per-target basis,
but with so many OBJECT targets, that is really tedious. Luckily,
add_compile_definitions() is scoped to the current directory and sub-
directories only.

src/libprojectM/CMakeLists.txt

@@ -20,6 +20,8 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
 
     # Additional preprocessor definitions for Windows builds
     add_compile_definitions(
+            NOMINMAX
+            WIN32_LEAN_AND_MEAN
             USE_FTGL
             USE_NATIVE_GLEW
             STBI_NO_DDS

src/libprojectM/Renderer/SOIL2/SOIL2.c

@@ -74,7 +74,6 @@
 
 #if defined( __WIN32__ ) || defined( _WIN32 ) || defined( WIN32 )
 	#define SOIL_PLATFORM_WIN32
-	#define WIN32_LEAN_AND_MEAN
 	#include <windows.h>
 	#include <wingdi.h>
 	#include <GL/gl.h>

src/libprojectM/Renderer/TextureManager.cpp

@@ -51,13 +51,8 @@ TextureManager::TextureManager(std::vector<std::string>& textureSearchPaths, int
         // blur5 =  64  <-  user sees this as "blur3"
         if (!(i&1) || (i<2))
         {
-#if defined WIN32 && defined max
-			w = max(16, w / 2);
-			h = max(16, h / 2);
-#else
 			w = std::max(16, w / 2);
 			h = std::max(16, h / 2);
-#endif /** WIN32 */
         }
         int w2 = ((w+3)/16)*16;
         int h2 = ((h+3)/4)*4;