* Add grpc plugins
* Add grpc plugins
* Translate wrap info to/from proto
* Add nil checks
* Fix nil marshaling errors
* Provide logging through the go-plugin logger
* handle errors in the messages
* Update the TLS config so bidirectional connections work
* Add connectivity checks
* Restart plugin and add timeouts where context is not availible
* Add the response wrap data into the grpc system implementation
* Add leaseoptions to pb.Auth
* Add an error translator
* Add tests for translating the proto objects
* Fix rename of function
* Add tracing to plugins for easier debugging
* Handle plugin crashes with the go-plugin context
* Add test for grpcStorage
* Add tests for backend and system
* Bump go-plugin for GRPCBroker
* Remove RegisterLicense
* Add casing translations for new proto messages
* Use doneCtx in grpcClient
* Use doneCtx in grpcClient
* s/shutdown/shut down/
* Start work on passing context to backends
* More work on passing context
* Unindent logical system
* Unindent token store
* Unindent passthrough
* Unindent cubbyhole
* Fix tests
* use requestContext in rollback and expiration managers
* Add automatic plugin reload
* Refactor builtin/backend
* Remove plugin reload at the core level
* Refactor plugin tests
* Add auto-reload test case
* Change backend to use sync.RWMutex, fix dangling test plugin processes
* Add a canary to plugin backends to avoid reloading many times (#3174)
* Call setupPluginCatalog before mount-related operations in postUnseal
* Don't create multiple system backends since core only holds a reference (#3176)
to one.
