Fix so that one can still link to wiki pages with # in their names.

Fix so that one can still link to wiki pages with # in their names.
(This was made difficult by the introduction of named tags, since
'[Page #1]' is now a link to anchor '1' in page 'Page'.

Now the ~ escape for page names should work: [Page ~#1].

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@2592 96ab9672-09ca-45d6-a79d-3d69d39ca109