src/awlist.scm: Turn to singleton.

* src/awlist.scm: Turn to singleton.
  (add-link): Rename to `awlist-add!'.  All callers updated.
  (set-done): Rename to `awlist-set-done!'.  All callers updated.
  (rem-link): Rename to `awlist-rem!'.  All callers updated.
  (get-list): Rename to `awlist-get'.  All callers updated.
  (get-uncompleted): Rename to `awlist-get-uncompleted'.  All
  callers updated.
  (clear): Rename to `awlist-clear!'.  All callers updated.
  (load-list): Rename to `awlist-load'.  All callers updated.
  (save-list): Rename to `awlist-save'.  All callers updated.
* src/awgetd.scm: Update.