Add full support for USPS DataMatrix

endpoints/logistics.tracking.php

@@ -2,7 +2,7 @@
 
 $trackinginfo;
 
-$code = $VARS["code"];
+$code = urldecode($VARS["code"]);
 $carrier = "";
 if (!empty($VARS["carrier"])) {
     $carrier = $VARS["carrier"];

lib/Tracking_USPS_gsbarcode.lib.php

@@ -14,8 +14,12 @@ class Tracking_USPS_gsbarcode {
             $code = substr($code, 1);
         }
         $codeparts = explode("\x1D", $code);
-
-        $realcode = $codeparts[1];
+        if (count($codeparts) == 1) {
+            $realcode = $codeparts[0];
+        } else {
+            // Has routing portion, let's skip that
+            $realcode = $codeparts[1];
+        }
 
         return Tracking::track($realcode, "usps");
     }