Patch: Escape character troubles (ITS#1753)

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B. Furuseth
Version: HEAD (2002-04-12)
OS: Linux
URL: http://folk.uio.no/hbf/OpenLDAP/escaped.txt
Submission from: (NULL) (158.36.148.34)


maildap could address buf[-1] if len was < 2.

REWRITE_SUBMATCH_ESCAPE is '%', not '\'.

librewrite and saslautz could walk past the end of a string which
ended with an escape character.