Refactoring of the segments Store interface Get method signature to
force the implementations to not use metainfo Client and be able for the
callers to batch requests.
* rename pkg/linksharing to linksharing
* rename pkg/httpserver to linksharing/httpserver
* rename pkg/eestream to uplink/eestream
* rename pkg/stream to uplink/stream
* rename pkg/metainfo/kvmetainfo to uplink/metainfo/kvmetainfo
* rename pkg/auth/signing to pkg/signing
* rename pkg/storage to uplink/storage
* rename pkg/accounting to satellite/accounting
* rename pkg/audit to satellite/audit
* rename pkg/certdb to satellite/certdb
* rename pkg/discovery to satellite/discovery
* rename pkg/overlay to satellite/overlay
* rename pkg/datarepair to satellite/repair
