Swap out w8r/martinez clipper for mfogel/polygon-clipping

This is a drop in replacement that performs better and yields more correct results
see also https://github.com/ideditor/location-conflation/pull/20

modules/services/vector_tile.js

@@ -3,7 +3,7 @@ import { dispatch as d3_dispatch } from 'd3-dispatch';
 import deepEqual from 'fast-deep-equal';
 import turf_bboxClip from '@turf/bbox-clip';
 import stringify from 'fast-json-stable-stringify';
-import * as martinez from 'martinez-polygon-clipping';
+import polygonClipping from 'polygon-clipping';
 
 import Protobuf from 'pbf';
 import vt from '@mapbox/vector-tile';
@@ -66,13 +66,13 @@ function vtToGeoJSON(data, tile, mergeCache) {
                     var merged = mergeCache[propertyhash];
                     if (merged && merged.length) {
                         var other = merged[0];
-                        var coords = martinez.union(
+                        var coords = polygonClipping.union(
                             feature.geometry.coordinates,
                             other.geometry.coordinates
                         );
 
                         if (!coords || !coords.length) {
-                            continue;  // something failed in martinez union
+                            continue;  // something failed in polygon union
                         }
 
                         merged.push(feature);

package.json

@@ -58,10 +58,10 @@
     "fast-json-stable-stringify": "2.1.0",
     "lodash-es": "~4.17.15",
     "marked": "~1.2.3",
-    "martinez-polygon-clipping": "0.7.0",
     "node-diff3": "2.1.0",
     "osm-auth": "1.1.0",
     "pannellum": "2.5.6",
+    "polygon-clipping": "~0.15.1",
     "rbush": "3.0.1",
     "whatwg-fetch": "^3.4.1",
     "which-polygon": "2.2.0"