Add a note in the docs about evaluation of Location sections

Add a note in the docs about evaluation of Location sections

The sections.html doc was missing, in my opinion, a direct
reference to the fact multiple Location blocks matching
a HTTP request will be evaluated in the order in which they
appear in the configuration files (same as Ifs, etc..).

Reworked a bit a single block of text to be a bit more readable.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1786709 13f79535-47bb-0310-9956-ffa450edef68