outline does not change heading line endings

[Lennart Borgman]

In outline there are two variables that are used to match heading lines, 
outline-regexp and outline-heading-end-regexp. When using outline-demote 
etc only the beginning of the heading is changed even if both this 
variables have similar values.

An example of this is if you try to edit wiki articles and have the 
variables set with something like this:

  (set (make-local-variable 'outline-regexp) "==+")
  (set (make-local-variable 'outline-heading-end-regexp) "==+")

Wiki header lines look like this:

= H1 =
== H2 ==
=== H3 ===

This is for Emacs 22.