Add follow-data animation

This adds a new animation mode which will track a data object
as it moves during the animation. The cameras position and focal
point will be updated each time-step to keep the data at the center
of the view.

In order to make this change the vtkPVCameraCueManipulator class
now needs access to the vtkSMSourceProxy for the data to follow
so that it may get the bounds from the data information. This
necessitated moving the animation classes from ClientServerCore
to the ServerManager module.

Change-Id: I9d82f749d459bb7598a96f77dd5dbc049e9bfce3
Add distributed Trivial producer for iPython use case.

Change-Id: Ie32bb4ae82b7c80f889dd5c304f247f1386a65e2
Adding option to load plugin at command line.

Two options are added to the command line namely --test-plugin and
--test-plugin-path. These will be used exclusively for loading and
testing individual plugins in paraview.

--test-plugin option takes the name of the plugin and loads it. The
  default plugin load paths are used with this option.

--test-plugin-path append the provided path to the actual search path.

Also adding two new cmake functions i.e add_client_plugin_tests and
add_client_server_plugin_tests which takes in Plugin name as an
additional option and passes it along with the --test-plugin command
line.

We are changing multiple plugin tests to use this options instead of
loading it in the test script. We also get rid of all xml code to load
the plugins from the test scripts.

Plugins have to be loaded on both client and server. The server-manager
on the client side typically helps load the plugin from default
location. However if the plugins were loaded from a different location
then the plugin-path needs to be specified not only at the client side
but also on the server side. This commit also achieves this.

The add_client[_server]_plugin test is extended to allow
plugin_path. The test driver is changed slightly to parse more options
sent to the server.

Change-Id: I15c26748979b280edae817cd34ea198cfe4a7bfe
Remove deprecated --server-postflags argument

Change-Id: I54030337685cccea8d635f49b753fe0f93deb247
Add missing plugin load argument for CoProcessing full workflow

Change-Id: I4f2737136f2b555ddcb594867bc49de639525241
Forward VTK to gerrit/master

Change-Id: I83071678ad8fa3a1d3ed8a5ac9d8fd04447b582e
Parse arguments in add_client_render_server_tests()

This fixes a bug in which the arguments for pvcrs tests were
not being parsed causing tests with plugins to fail.

Change-Id: If5c77c96f24f6a6f7cf72da9dbb6b805422b2b61
Merge topic 'add-test-plugin-option-v2'

6035cd7 Parse arguments in add_client_render_server_tests()
fa9a9f7 Add missing plugin load argument for CoProcessing full workflow
995c6f0 Remove deprecated --server-postflags argument
5aeb9eb Adding option to load plugin at command line.
Merge topic 'follow-data-animation'

d9665ad Add follow-data animation
Merge topic 'forward-to-vtk-master'

9b6da2f Forward VTK to gerrit/master
Merge topic 'ipython_trivial_producer'

4298ea8 Add distributed Trivial producer for iPython use case.