[meta] Application.* API will be removed

[Infocatcher]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1090880

• Bookmarks Folder
  
  Application.prefs.getValue()/setValue()

Application.name
• Custom Buttons Editor: Toggle on Top
  
  Application.storage.get()/set()
• Source Editor
  
  Application.storage.get()/set()
• Cookies Permissions
  
  Application.storage.get()/set()
• Extensions Developer Tools
  
  Application.restart()

Application.quit()
• Extensions Installer
  
  Application.restart()
• Toggle Flash
  
  Application.prefs.getValue()
• Toggle Restartless Add-ons
  
  Application.prefs.getValue()