Fixed bug with top level actions breaking searchable menus.
Fixed bug with top level actions breaking searchable menus.

When actions are triggered in searchable menus, they are presumed to exist beyond multiple shows. Top level actions (no submenus) were being destroyed when the menu is cleared, which happens during the following show(). We prevent destruction by adding the triggered action to the search results submenu. Fixes #399.

paulondc/gaffer,chippey/gaffer,boberfly/gaffer,davidsminor/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,hradec/gaffer,cedriclaunay/gaffer,johnhaddon/gaffer,appleseedhq/gaffer,boberfly/gaffer,ivanimanishi/gaffer,hradec/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,paulondc/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,paulondc/gaffer,goddardl/gaffer,davidsminor/gaffer,ivanimanishi/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,davidsminor/gaffer,goddardl/gaffer,ivanimanishi/gaffer,cedriclaunay/gaffer,paulondc/gaffer,chippey/gaffer,goddardl/gaffer,lucienfostier/gaffer,johnhaddon/gaffer,cedriclaunay/gaffer,hradec/gaffer,goddardl/gaffer,boberfly/gaffer,davidsminor/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,hradec/gaffer,hradec/gaffer,appleseedhq/gaffer,chippey/gaffer,ImageEngine/gaffer,chippey/gaffer,GafferHQ/gaffer,boberfly/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,ivanimanishi/gaffer,ImageEngine/gaffer,cedriclaunay/gaffer,andrewkaufman/gaffer,andrewkaufman/gaffer,lucienfostier/gaffer,johnhaddon/gaffer