elmo-util.el (elmo-max-of-list): Refactored.
elmo-util.el (elmo-max-of-list, elmo-cache-get-path-subr, elmo-warning): Explicit function's symbols.
elmo-util.el (elmo-max-of-list): Fix the last change for the case argument is nil.
Improve performance of uniquifying large list of sortable numbers.
wl-summary.el (wl-summary-default-subject-filter): Minor refactoring.
Keep multiple parent Message-IDs in msgdb.
elmo-util.el (elmo-list-diff): Simplified.  Sort each element of return value.
wl-summary.el (wl-summary-insert-thread): Report progress.