Initializes all the basic context required for the admin center.

• Passes execution onto the relevant admin section.
• If the passed section is not found it shows the admin home page.
• Uses the "Admin" language and templates
• Sets up $admin_areas and $menuOptions arrays
• $admin_areas - array defining menu structure for the admin center
• $menuOptions - array containing information about the various menu options
• Passes both arrays off to createMenu()