Cleaning up temporal markers

[Ikumi Keita]

Hi all,

Elisp reference recommends to make markers point nowhere when they are
no longer necessary:
,----
|    Insertion and deletion in a buffer must check all the markers and
| relocate them if necessary.  This slows processing in a buffer with a
| large number of markers.  For this reason, it is a good idea to make a
| marker point nowhere if you are sure you don’t need it any more.
| Markers that can no longer be accessed are eventually removed (*note
| Garbage Collection::).
`----

AUCTeX sometimes leaves temporal markers without clearing them up. So I
propose to apply the attached patch.

I'd appreciate if you'd give it a try and send back feedbacks if any. (I
haven't tested changes for dinbrief.el and letter.el myself.)

Best regards,
Ikumi Keita

0001-Clean-up-temporal-markers.patch
Description: Clean up temporal markers