Fix alignment in a <highlight> block.

Fix alignment in a <highlight> block.
Add directive name in <default> so that 'quickreference.html' is generated with the corresponding default value.
Avoid some duplicated words (i.e. 'to to').
Fix some incorrect directive name in some description.
Fix the description of 'AuthFormBody' which was a copy&paste of 'AuthFormMethod'.
Remove some useless <var></var> around 'On|Off'.

(r1869053 in trunk)

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1869054 13f79535-47bb-0310-9956-ffa450edef68