o.c.startup: Application no longer closes Display

It's usually closed by the RCP framework. Additional close used to be
required for Mac OS X, but causes crash on Eclipse 4.4(.2).
o.c.security.ui: Status bar 'click' opens info view
o.c.ui.util: Removed unused imports from ImageStackWidget

import of internal.FolderLayout caused Eclipse 4.2.2 compile error