Add Grid.hide_columns() convenience method

tailbone/grids/core.py

@@ -130,6 +130,10 @@ class Grid(object):
         if key in self.columns:
             self.columns.remove(key)
 
+    def hide_columns(self, *keys):
+        for key in keys:
+            self.hide_column(key)
+
     def append(self, field):
         self.columns.append(field)