* smp server: remove STM function from MsgStore
* polymorphic MsgStore
* jourmal storage for messages (WIP)
* more journal, test setup
* writeMsg
* test
* tryDelMsg
* delMsgQueue
* remove MsgStoreClass instance of existential wrapper for Msg stores
* store config
* extract common logic out of store instances
* add store type to config
* open journals, cache last message, tests pass
* CLI commands
* refactor import/export messages
* cli commands to import/export journal message store
* export journal without draining, import/export tests
* journal command
* import/export progress
* better progress info
* only log queue state once when importing
* logs
* handle IO errors in journal store, return as STORE error
* recover from state file errors
* fix message files after crash
* fix messages folder