Return multiple turbo-carto errors

Closes #541

lib/cartodb/models/mapconfig/adapter/turbo-carto-adapter.js

@@ -32,12 +32,22 @@ TurboCartoAdapter.prototype.getMapConfig = function (user, requestMapConfig, par
         parseCartoQueue.defer(self._parseCartoCss.bind(self), user, params, layer, index, layerId);
     });
 
-    parseCartoQueue.awaitAll(function (err, layers) {
+    parseCartoQueue.awaitAll(function (err, results) {
         if (err) {
             return callback(err);
         }
 
-        requestMapConfig.layers = layers;
+        var errors = results.reduce(function(errors, result) {
+            if (result.error) {
+                errors.push(result.error);
+            }
+            return errors;
+        }, []);
+        if (errors.length > 0) {
+            return callback(errors);
+        }
+
+        requestMapConfig.layers = results.map(function(result) { return result.layer; });
 
         return callback(null, requestMapConfig);
     });
@@ -70,7 +80,7 @@ var tokensQueryTpl = dot.template([
 
 TurboCartoAdapter.prototype._parseCartoCss = function (username, params, layer, layerIndex, layerId, callback) {
     if (!shouldParseLayerCartocss(layer)) {
-        return callback(null, layer);
+        return callback(null, { layer: layer });
     }
 
     var pg = new PSQL(dbParamsFromReqParams(params));
@@ -88,14 +98,14 @@ TurboCartoAdapter.prototype._parseCartoCss = function (username, params, layer,
                 context: err.context
             };
 
-            return callback(error);
+            return callback(null, { error: error });
         }
 
         // Try to continue in the rest of the cases
         if (cartocss) {
             layer.options.cartocss = cartocss;
         }
-        return callback(null, layer);
+        return callback(null, { layer: layer });
     }
 
     var layerSql = layer.options.sql;
@@ -107,7 +117,7 @@ TurboCartoAdapter.prototype._parseCartoCss = function (username, params, layer,
             if (err) {
                 var error = new Error('turbo-carto: ' + err.message);
                 error.type = 'turbo-carto';
-                return callback(error);
+                return processCallback(error);
             }
 
             resultSet = resultSet || {};