Fixes around around and metadata.

FIX: gs_upload_content_v2 correctly send mdusr
FIX: mdusr are now correctly set while using gs_uplaod_content_v2
ADD: method gs_upload which allow mdusr & stgpol

Thank you, CDE.

Change-Id: I1c3e01dfaf823332cbb12ecbb872626831b346a0