* lsdb.el: Require pces for find-coding-system.

* lsdb.el: Require pces for find-coding-system.
(lsdb-file-coding-system): Call find-coding-system when setting the default value.
(lsdb-save-file): Convert coding-system-name into string.
(lsdb-lookup-records): Splitted from lsdb-mode-lookup.
(lsdb-mu-attribution): New function.
(lsdb-mu-set-attribution): New function.
(lsdb-mu-get-prefix-method): New function.
(lsdb-mu-get-prefix-register-method): New function.
(lsdb-mu-get-prefix-register-verbose-method): New function.
(lsdb-mu-insinuate): New function.
(lsdb-mu-history): New variable.