Fixed config file home dir path handling under Windows.
Fixed config file home dir path handling under Windows.


GoogleCloudPlatform/gsutil,GoogleCloudPlatform/gsutil,chriskuehl/gsutil-debian,ttiurani/gsutil,craigcitro/gsutil,dtjackson/gsutil,dimfeld/gsutil,mattdr/gsutil,fishjord/gsutil,BrandonY/gsutil