What: Change cmd/uplink to use scopes
It moves the fields that will be subsumed by scopes into an explicit legacy section and hides their configuration flags.
Why: So that it can read scopes in from files and stuff
* pkg/server: don't use global logger
* satellite/overlay: use correct logger
* pkg/kademlia: use correct logger
* linksharing: use conventional way to pass in logger
* use zaptest in tests
* 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
