* Move some test helper stuff from the vault package to a new helper/testhelpers/corehelpers package. Consolidate on a single "noop audit" implementation.
* port SSCT OSS
* port header hmac key to ent and generate token proto without make command
* remove extra nil check in request handling
* add changelog
* add comment to router.go
* change test var to use length constants
* remove local index is 0 check and extra defer which can be removed after use of ExternalID
* porting identity to OSS
* changes that glue things together
* add testing bits
* wrapped entity id
* fix mount error
* some more changes to core
* fix storagepacker tests
* fix some more tests
* fix mount tests
* fix http mount tests
* audit changes for identity
* remove upgrade structs on the oss side
* added go-memdb to vendor