keepalive: Proper macos implementation.
keepalive: Proper macos implementation.

Change-Id: I8a84b0585424c3e84d4fe866dd577a2f35579d57
Reviewed-on: http://gerrit.aldebaran.lan/22406
Reviewed-by: mnottale <e3ccf1b6558404e921a21fa09cebb1153b50ec36@aldebaran-robotics.com>
Tested-by: mnottale <e3ccf1b6558404e921a21fa09cebb1153b50ec36@aldebaran-robotics.com>

bsautron/libqi,vbarbaresi/libqi,aldebaran/libqi,aldebaran/libqi,aldebaran/libqi