OSX Launchd Startup Manage with Preference Pane

OSX Launchd Startup Manage  with Preference Pane

OpenAFS preference pane has been updated to manage the new launchd startup mode. Has been delete the custom startup and shutdown file now is user the /Library/OpenAFS/Tools/root.client/usr/vice/etc/afs.rc

OpenAFS.postinstall has been modified to remove the old existing /Library/StartupItems/OpenAFS directory
OpenAFS.pre_upgrade has been modified to shutdown daemon, if it is runnig, and remove the old preference pane to permit the one to be installed

Reviewed-on: http://gerrit.openafs.org/578
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>