Add support for configuration of MacOS 10.10 "Yosemite"

Add support for configuration of MacOS 10.10 "Yosemite"

This is just the configuration part of the patch submitted
in the RT ticket. The packaging part will will follow in the
next change.

FIXES 131946

Change-Id: Ic8835b1ddf317600483505a2d94d9f3568720804
Reviewed-on: http://gerrit.openafs.org/11560
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: D Brashear <shadow@your-file-system.com>