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/>.

js/util/TrackEdges.js

@@ -0,0 +1,79 @@
+/**
+ * The track messages and track analysis panels share some functionality
+ * which is defined in this class to prevent code duplication.
+ *
+ * @type {L.Class}
+ */
+BR.TrackEdges = L.Class.extend({
+    /**
+     * List of indexes for the track array where
+     * a segment with different features ends
+     *
+     * @type {number[]}
+     * @see BR.TrackMessages
+     */
+    edges: [],
+
+    /**
+     * @param {Array} segments
+     */
+    initialize: function(segments) {
+        this.edges = this.getTrackEdges(segments);
+    },
+
+    /**
+     * Find the indexes where a track segment ends, i.e. where the waytags change.
+     *
+     * Used in TrackMessages and TrackAnalysis for highlighting track segments.
+     *
+     * @param {Array} segments
+     *
+     * @return {number[]}
+     */
+    getTrackEdges: function(segments) {
+        var messages,
+            segLatLngs,
+            length,
+            si,
+            mi,
+            latLng,
+            i,
+            segIndex,
+            baseIndex = 0,
+            edges = [];
+
+        // track latLngs index for end node of edge
+        for (si = 0; si < segments.length; si++) {
+            messages = segments[si].feature.properties.messages;
+            segLatLngs = segments[si].getLatLngs();
+            length = segLatLngs.length;
+            segIndex = 0;
+
+            for (mi = 1; mi < messages.length; mi++) {
+                latLng = this.getMessageLatLng(messages[mi]);
+
+                for (i = segIndex; i < length; i++) {
+                    if (latLng.equals(segLatLngs[i])) {
+                        break;
+                    }
+                }
+                if (i === length) {
+                    i = length - 1;
+                }
+
+                segIndex = i + 1;
+                edges.push(baseIndex + i);
+            }
+            baseIndex += length;
+        }
+
+        return edges;
+    },
+
+    getMessageLatLng: function(message) {
+        var lon = message[0] / 1000000,
+            lat = message[1] / 1000000;
+
+        return L.latLng(lat, lon);
+    }
+});