Added a new ParaViewWeb application to be used only for testing.

Added a new python server and a very basic index.html for a new
ParaViewWeb application which will be used only to test some new
module registration functions and to test the various paraview
web protocols.  Also added some bits to the web applications
CMakeLists.txt which will copy the new app to the build tree only
when testing is enabled.  Modified this same file to recursively
copy the new test folders inside any web application to the build
tree, but again, only when testing is enabled.

Change-Id: I65dbcd2be7bd6a0ffbc5c496069ebacb26046db4
Added several python test scripts to new test directories under web apps.

These test scripts get launched by the vtk.web.server module in a separate
Python thread.  Each test uses either Python requests module or selenium
modules to interact with a specific ParaViewWeb application.

Added CTests that test several ParaViewWeb applications.

Tests are now run on WebVisualizer and WebFileLoader, they start the
servers, passing new flags to server.py which indicate that a test
script should be run against the server.
Added module registration calls to each of these ParaViewWeb libs.

Now each module registers itself using a unique name based on the
file name.  This registration can later be verified for testing
purposes or in web application code.

Change-Id: I038435dfe68310052ac105eb60888f283ab06ca4
Added a CMake macro to find the selenium drivers on a system.

Added a ParaView test macro for adding web-based tests.

This macro takes as arguments a list of browsers that are required by
the set of test scripts, as well as a list of the required Python
modules.  The macro checks that the selenium browser drivers are
actually present, and that the required Python modules are present as
well, before adding web-based tests for each browser (adding each test
script with every browser).

Change-Id: Ieaa7f918303d2dfd777e7ed98ffe3c9d41038845
Merge topic 'paraview-web-client-tests' into next

d101e23 Added a CMake macro to find the selenium drivers on a system.
f0c0290 Added module registration calls to each of these ParaViewWeb libs.
078370e Added several python test scripts to new test directories under web apps.
46b9b02 Added a new ParaViewWeb application to be used only for testing.