i don't know why we returned  a space when there was no delimiter - but this totally breaks when parsing `".."`. however, this causes the test https://github.com/phpcr/phpcr-api-tests/blob/master/tests/06_Query/CharacterTest.php#L117 to fail. i really don't see why we get `foo&bar&baz` from `foo & bar&baz` there, as the unit test below shows that parsing that string will preserve the spaces.