Fail hard when re2c is not found or the version requirement not met

With 7.2, the binary SDK supplies the minimal required version, thus no
reason to fail later at the compilation time.

win32/build/confutils.js

@@ -2910,14 +2910,10 @@ function toolset_setup_project_tools()
 		var intmin =  (nm[1]-0)*10000 + (nm[2]-0)*100 + (nm[3]-0);
 
 		if (intvers < intmin) {
-			STDOUT.WriteLine('WARNING: The minimum RE2C version requirement is ' + MINRE2C);
-			STDOUT.WriteLine('Parsers will not be generated. Upgrade your copy at http://sf.net/projects/re2c');
-			DEFINE('RE2C', '');
-		} else {
-			DEFINE('RE2C_FLAGS', '');
+			ERROR('The minimum RE2C version requirement is ' + MINRE2C);
 		}
 	} else {
-		STDOUT.WriteLine('Parsers will not be regenerated');
+		ERROR('re2c is required')
 	}
 	PATH_PROG('zip');
 	PATH_PROG('lemon');