Revive screen space browser and add example (#932)

* Revive screen space browser and add example
* Add reload triggerproperty and change autoplay policy

src/rendering/dashboard_lua.inl

@@ -48,7 +48,13 @@ int addDashboardItem(lua_State* L) {
         }
         lua_settop(L, 0);
 
-        global::dashboard.addDashboardItem(DashboardItem::createFromDictionary(d));
+        try {
+            global::dashboard.addDashboardItem(DashboardItem::createFromDictionary(d));
+        }
+        catch (const ghoul::RuntimeError& e) {
+            LERRORC("addDashboardItem", e.what());
+            return ghoul::lua::luaError(L, "Error adding dashboard item");
+        }
 
         ghoul_assert(lua_gettop(L) == 0, "Incorrect number of items left on stack");
         return 0;

src/rendering/screenspacerenderable.cpp

@@ -614,9 +614,8 @@ void ScreenSpaceRenderable::draw(glm::mat4 modelTransform) {
     unbindTexture();
 }
 
-void ScreenSpaceRenderable::bindTexture() {}
-
-void ScreenSpaceRenderable::unbindTexture() {}
+void ScreenSpaceRenderable::unbindTexture() {
+}
 
 
 } // namespace openspace