Consistency in Windows ifdefs/windows.h includes

Changing all defined(_WINDOWS) to defined(_WIN32)

Defining WIN32_LEAN_AND_MEAN in all files except those in Archutils/Win32

src/CommandLineActions.cpp

@@ -21,7 +21,8 @@
 #include <vector>
 
 // only used for Version()
-#if defined(_WINDOWS)
+#if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <conio.h>
 #endif
@@ -51,7 +52,7 @@ static void LuaInformation()
  * regardless of any preferences (tested by shakesoda on Mac). -aj */
 static void Version()
 {
-	#if defined(WIN32)
+	#if defined(_WIN32)
 		RString sProductID = ssprintf("%s", (std::string(PRODUCT_FAMILY) + product_version).c_str() );
 		RString sVersion = ssprintf("build %s\nCompile Date: %s @ %s", ::sm_version_git_hash, version_date, version_time);