Start coding OSX Backgrounder Application, for OpenAFS Preference Pane, that user...

Start coding OSX Backgrounder Application, for OpenAFS Preference Pane, that user NSStatusItem

To prevent future compatibility with osx we must use NSStatusItem instead NSMenuExtra that is not documented api.
For this has been created a background only application that will manage all function managed by current NSMenuExtra

Reviewed-on: http://gerrit.openafs.org/261
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit f52f509962fbaade008f5dc6c2f8a3bece70c13c)
Change-Id: I69815922f40ea51c380c7300648e9dfa3bb809b5
Reviewed-on: http://gerrit.openafs.org/947