General usability improvements

* Reevaluate all featuers stroke widths for shadow, casing, stroke
* Shadow width is important to make sure all features are easily clickable
* Casing width is important to see oneway arrows
* Make sure all line styles have normal and low-zoom variants
* Show directional arrows for all waterway types

modules/behavior/breathe.js

@@ -94,8 +94,8 @@ export function behaviorBreathe() {
                 p.tag = tag;
                 p.from.opacity = opacity * 0.6;
                 p.to.opacity = opacity * 1.25;
-                p.from.width = width * 0.9;
-                p.to.width = width * (tag === 'circle' ? 1.5 : 1.25);
+                p.from.width = width * 0.7;
+                p.to.width = width * (tag === 'circle' ? 1.5 : 1);
                 params[d.id] = p;
             });
     }

modules/osm/tags.js

@@ -35,6 +35,9 @@ export var osmOneWayTags = {
         'yes': true
     },
     'waterway': {
+        'canal': true,
+        'ditch': true,
+        'drain': true,
         'river': true,
         'stream': true
     }