Add sidebar tab with route analysis data

- adds a new analysis tab in the sidebar
- the analysis tab shows length distribution for different way types, surface, and smoothness
- table rows can be hovered/clicked to highlight the according segments on the map (similar behaviour as the detailed data table)
- localization is implemented for `de` and `en`
- the method for finding segment edges was extracted from `js/control/TrackMessages.js` into `js/util/TrackEdges.js` as it's used in the new analysis class too (the Gulp config was changed to reflect that)

Notes:

I had the idea to use the *DataTable* plugin for rendering the tables but decided against it. The only meaningful way to sort such a table is by the length column and that's already the case. So it's just three plain, old HTML tables, rendered by jQuery.

For meaningful statistics the `processUnusedTags` setting has to be enabled in the routing profile. Only in this case the BRouter backend includes all needed tags (`highway`, `surface`, and `smoothness`) for *every* route segment in the response. I’ve enabled that setting for all profiles at my BRouter-web instance at <https://brouter.m11n.de/>.

locales/de.json

@@ -180,6 +180,31 @@
     "itinerary": {
       "title": "Reiseroute"
     },
+    "analysis": {
+      "title": "Analyse",
+      "header": {
+        "highway": "Weg",
+        "surface": "Material",
+        "smoothness": "Beschaffenheit"
+      },
+      "table": {
+        "category": "Art",
+        "length": "Länge",
+        "total_known": "Gesamt bekannt:",
+        "unknown": "Unbekannt"
+      },
+      "data": {
+        "highway": {
+          "living_street": "living street"
+        },
+        "surface": {
+          "paving_stones": "paving stones"
+        },
+        "smoothness": {
+          "very_bad": "very bad"
+        }
+      }
+    },
     "layers": {
       "category": {
         "base-layers": "Grundkarten",