GPII-568: Preference management tools detect the user's OS and select aux schema accordingly.

This is related to JIRA issue http://issues.gpii.net/browse/GPII-568.
Currently, it leaves all adjusters in for PCP in both Windows and Linux cases. This will be sorted out in the context of http://issues.gpii.net/browse/GPII-565 "PCP should show only settings that can be applied live ".