switched the default compiler version to gcc 4.0 so that it builds properly under 10.5, Debug mode

platform/macosx/love.xcodeproj/project.pbxproj

@@ -1686,6 +1686,7 @@
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = NO;
 				GCC_TREAT_NONCONFORMANT_CODE_ERRORS_AS_WARNINGS = NO;
+				GCC_VERSION = 4.0;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = NO;
 				GCC_WARN_ABOUT_MISSING_PROTOTYPES = NO;