Manual merge of Pull Request #233 via @gilesc50 (fixed a typo, which means that OpenLayers icons now show as a missing picture, rather than not showing at all. Its not a complete fix for OpenLayers icons missing, but it does move it forwards)
Manual merge of Pull Request #234 via @gilesc50 (Remove OpenSpace v1.2 specific error handling code which is obsoleted in OpenSpace v4.0)