Split long lines

Align examples on the left to be consistent
Add some missing <em> in syntax description
Add some hyperlinks to modules and directives
Fix some bogus <directive type="section"> usage
Fix typo
(r1738690 and r1738693 in trunk)

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1738698 13f79535-47bb-0310-9956-ffa450edef68