use Result class in reverse geocoding

Also simplifies the reverse algorithm slightly by no longer
having an additional distance lookup.

lib/lib.php

@@ -615,3 +615,23 @@ function createPointsAroundCenter($fLon, $fLat, $fRadius)
     }
     return $aPolyPoints;
 }
+
+function closestHouseNumber($aRow)
+{
+    $fHouse = $aRow['startnumber']
+                + ($aRow['endnumber'] - $aRow['startnumber']) * $aRow['fraction'];
+
+    switch ($aRow['interpolationtype']) {
+        case 'odd':
+            $iHn = (int)($fHouse/2) * 2 + 1;
+            break;
+        case 'even':
+            $iHn = (int)(round($fHouse/2)) * 2;
+            break;
+        default:
+            $iHn = (int)(round($fHouse));
+            break;
+    }
+
+    return max(min($aRow['endnumber'], $iHn), $aRow['startnumber']);
+}