fix TestRequest

The testcases which checked against >=0 were not correct.

$INPUT is instantiated  in inc/init.php and doku.php calls inc/init.php with require_once so $INPUT wont be updated to the new requested id.

I had to add $ID and $INFO as global variables to execute() to get the tests working. (see http://www.php.net/manual/de/language.variables.scope.php#63500 and http://www.php.net/manual/de/language.variables.scope.php#3596)

maybe the are some more globals we have to add here...