Ensure error thrown uses 'type' not 'name'

lib/less/tree/operation.js

@@ -15,12 +15,12 @@ tree.Operation.prototype.eval = function (env) {
             if (this.op === '*' || this.op === '+') {
                 temp = b, b = a, a = temp;
             } else {
-                throw { name: "OperationError",
+                throw { type: "Operation",
                         message: "Can't substract or divide a color from a number" };
             }
         }
         if (!a.operate) {
-            throw { name: "OperationError",
+            throw { type: "Operation",
                     message: "Operation on an invalid type" };
         }
 

test/less/errors/color-operation-error.less

@@ -0,0 +1,3 @@
+.a {
+  prop: (3 / #fff);
+}

test/less/errors/color-operation-error.txt

@@ -0,0 +1,2 @@
+OperationError: Can't substract or divide a color from a number in {path}color-operation-error.less:null:-1
+1   prop: (3 / #fff);