Item12526: update anchor regex to match Foswiki-generated anchors


git-svn-id: http://svn.foswiki.org/trunk@16782 0b4bb1d4-4e5a-0410-9cc4-b2b747904278
Item12526: add regression test


git-svn-id: http://svn.foswiki.org/trunk@16783 0b4bb1d4-4e5a-0410-9cc4-b2b747904278