OC-Etag?

[moscicki]

We should clarify OC-Etag header vs standard Etag.

@dragotin: any insights?

[dragotin]

According to
https://github.com/owncloud/client/blob/master/src/libsync/owncloudpropagator_p.h#L42
we support both forms, for historical reasons. The ETag however should be considered depricated.