Allow parsing of xyz chunks containing altitude am: 23b98e35

            // Worst case the location string length would be 18,

            // for instance +90.0000-180.0000, without the trailing "/" and

            // the string length + language code.

            char buffer[18];

            // the string length + language code, and some devices include

            // an additional 8 bytes of altitude, e.g. +007.186

            char buffer[18 + 8];

            // Substracting 5 from the data size is because the text string length +

            // language code takes 4 bytes, and the trailing slash "/" takes 1 byte.