* Added: the capability key for section and field arrays which sets access rights to the form elements.
* Added: a hidden tab page which belongs to the first page with a link back-and-forth in the demo plugin.
* Changed: the required WordPress version to 3.2 as the newly used filter option_page_capability_{$pageslug} requires it.
* Fixed: an issue that setting a custom capability caused the "Creatin' huh?" message and the user could not change the options.
* Added: the HideInPageTab() method which hides a specified in-page tab yet still accessible by the direct url.
* changed: the method name RenderInPageTabs() to GetInPageTabs() since it did not print anything but returned the output string.