nens/lizard-client — pull request #110 by arjenvrielink (2014-09-17 14:35:32+00:00)
Title: Fix broken impervious surfaces

### Problem
relate pipe to surface tool was broken https://github.com/nens/lizard-nxt/issues/313

### Solution
* Add check for non-existing surface_ids
* Get leaflet overlaypane dynamically

Debugging locally, suddenly the feature worked again without really understanding why. Anyway, these fixes are improvements.