[Review] Request from 'aduffeck' @ 'SUSE/machinery/review_141120_filter_special_mounts_when_inspecting_unmanaged_files'

Please review the following changes:
  * 088ac22 Filter special mounts when inspecting unmanaged files,e.g. procfs mounts
  * ed4bf05 Add MountPoints#special which returns a list of special mounts like proc
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