fix metadata overwrite during a post request

During a post request, the object-server is ovewriting
the existing object metadata. This fix prevents the overwrite
of the system metadata while it allows for the user to
add/remove user metadata

Change-Id: Ic62cd064589b625ee425a9934be8766650622c13
Signed-off-by: Thiago da Silva <thiago@redhat.com>
Reviewed-on: http://review.gluster.org/6254
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>
Signed-off-by: Thiago da Silva <thiago@redhat.com>
Reviewed-on: http://review.gluster.org/6315
Functional Tests for gswauth_cli

This test suite plans to tests following gswauth commands:-
1. swauth-prep
2. swauth-add-account
3. swauth-delete-account
4. swauth-add-user
5. swauth-delete-user
6. swauth-set-account-service
7. swauth-cleanup-tokens
8. swauth-list
It uses 'commands' python module to execute gswauthcommands,
and capture the status and output of commands followed by
asserts to verify if the captured status and output is same
as expected ones.This initial draft has tests for first 1-5
commands.

Change-Id: I8591884e87c6ffd88446aacd04a1db2daab2d189
Signed-off-by: Pushpesh Sharma <psharma@redhat.com>
Reviewed-on: http://review.gluster.org/6277
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>