After adding a new point, only compute the distance and the heading between the new and the previous point (instead of all points).

Add route save button. Routes should be saved after adding (or removing) points.
Saving route will:
- Update distance and heading between every point
- Compute total length of route
- Update encoded path used by static map images at frontpage

client/bicyclesim-meteor.html

@@ -192,6 +192,8 @@
       {{#if can_edit}}<a href="#" class="remove"><i class="icon-remove-sign"></i></a>{{/if}}
     </li>
   {{/each}}
-    {{#if can_edit}}<li class="new-point"><button type="button" class="btn"><i class="icon-plus-sign"></i></button></li>{{/if}}
+    {{#if can_edit}}
+    <li class="actions"><button type="button" class="btn new-point"><i class="icon-plus-sign"></i> Uusi</button> <button type="button" class="btn save{{#if saved}} btn-success{{else}} btn-warning{{/if}}"><i class="icon-save"></i> Tallenna</button></li>
+    {{/if}}
   </ol>
 </template>