Merge r290712, r290720, r290723 from trunk:

The arrow indicator for a glossary link was cute, but I found it way too
disturbing to the flow of text.  Here I replace it with a dashed-unline.
Also, allow the omission of the ref attribute where the glossary term is
exactly equal to the link contents.


Omit reference to pre-2.0.48 versions.


Add some <glossary> markup for regular expression and regex.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@290725 13f79535-47bb-0310-9956-ffa450edef68