Improve testcase for landmarks and other structural elements

[philljenkins]

use/copy a test case from Steve Faulkner's original test case for HTML 5 Structural Elements:

see SteveF's test page: https://rawgit.com/stevefaulkner/HTML5accessibility/master/tests/structural-elements.html

Summary

Enhance the Checker testcases by including all the HTML 5 structural elements

SME and/or Dev work only, no design.

Justification

Adding this test case will, as so does many other test cases, trigger other rules, but the intent is to only "check automatically" in the landmark test results in the automated builds of the Checker

Screen shot of test case:

[tombrunet]

@philljenkins Is this a valid testcase? What should / shouldn't trigger?