Delete the active journal's file without re-passing the path

[demyan]

After a journal is flushed/persisted, the only way to delete it is to close it and shell out to rm, re-deriving the filename ourselves:

  (.log.close)
  (.sys.exec (format "rm -f %.log" base))   ;; current workaround

Proposed:

  (.log.<remove|del>)    ;; close the active journal (if open) and unlink ALL its segment files

No path argument - it acts on the current journal, the same one .log.open/.log.write/.log.close operate on.