Fixed some broken tests of the new ParaViewWeb test application.

One broken test was the python test which retrieved the index.html
and verified presence of script includes.  Now this test actually
attempts to load the needed javascript files and checks the HTTP
return code.

The other broken test was due to assuming known indices of data
items in the ParaViewData repository.

Change-Id: Idf22d90f48c12146850f5ec89d388d9552dc191c
Merge topic 'pvweb-test-app' into next

05ec32c Fixed some broken tests of the new ParaViewWeb test application.