Fix Permissions Across Copied Pages

Fix permissions carrying accross copied pages.

`Page::getPermissionObjectIdentifier()` tries to call
`Page::getPermissionCollectionID()` but this is set to the original
page
upon `Page::duplicate()`

- if set to `OVERRIDE` call `Page::setPermissionsToManualOverride()`

http://www.concrete5.org/developers/bugs/5-6-1-2/permissions-problem-when-copying-pages/
http://www.concrete5.org/developers/bugs/5-6-1-2/page-permissions-bug-when-copyingcloning-page/