Backport of r1567382, r1567404 from tomcat/trunk:
Followup to r1567148
Expand validation tests for merged web.xml:
add default conf/web.xml into the merged one.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1567408 13f79535-47bb-0310-9956-ffa450edef68