nodehierarchy 6.x-2.1

This release does not contain any database updates and the nodehierarchy folder can be replaced with ease.

Fixes the following:

• #1125298: Fieldset is not properly restricted and shows up blank: by Mark Carver, jbylsma
• #809542: Menu options hidden when "show item in menu" set to "always": by davidmprice, jbylsma
• #977236: Nodehierarchyaccess.info missing core: by jbylsma
• Fixed issue with upgrade from Node Hierarchy 1.x that was removing default parents: by ronan
• Memory footprint and performance improvements by rolling back the code to test if a view is compatible nodehierarchy view to an earlier version: by ronan
• #1077392: Fatal error: Call to undefined function menu_overview_form(): by ronan