Fix typo in docs.

Backport of r1643570 form trunk.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc8.0.x/trunk@1643571 13f79535-47bb-0310-9956-ffa450edef68
Simplify XPath expression. Not a functional change (no changes in the output).
Merged r1643045 from tomcat/trunk.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc8.0.x/trunk@1643581 13f79535-47bb-0310-9956-ffa450edef68
Fix ambiguity of anchors on config/valve.html page.
Change algorithm for generation of unambiguous anchor names.

The issue was reported via documentation comments system.

Sample old and new anchors:
Access_Logging/Introduction
Access_Log_Valve/Introduction, Extended_Access_Log_Valve/Introduction

Merged revision 1643054 from tomcat/trunk.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc8.0.x/trunk@1643582 13f79535-47bb-0310-9956-ffa450edef68