Add exporter mechanism for catalyst

This allow users to register arbitrary data exporter
which will then be called after each timestep to
export or process the data the way they want.

They just need to implement the 2 following methods:

   UpdatePipeline(time)
   Finalize()

Change-Id: Iabad816c3fac4a3ff60fffccf6fd59051fff8d27
Calling finalize on existing Catalyst pipelines.

Change-Id: Ib06c8c52f8e3f79690b697ec4e805b494d3801c1
Fix 14931: The Histogram filter does not Calculate Averages by default.

Change-Id: I941adcf213d1d983bd608fa93184b9c0ee915eae
Add an 'CalculateAverages' to XYHistogram test.

This property is not set by default now.

Change-Id: Ie5d7589b9b9b46e9e81b7c3327c4d971392a111f
Fixing LoadDistributedPlugin() works for Catalyst.

This works for both the build directory and instal directory
for a PV development install, as long as the build directory
still exists. This is because it looks for the plugin
library in the build directory in both cases.
Also getting rid of trailing white space and a compile warning.

Change-Id: I1a3457f90f51eaf112bccba8fb949bcf4f7f3be7
BUG #14994. Fix issue with text source/representation in parallel.

With changes to the pipeline, vtkPVTextSource was only getting called on
the root-node. Hence text was not available on satellites.
vtkTextSourceRepresentation assumed that text was available on all nodes
to avoid redistribution of data. Hence we failed with missing text
errors when rendering on satellites. Fixed that by making sure that
vtkPVTextSource gets executed on all ranks.

Also fixed vtkTextSourceRepresentation to not raise errors when empty
text is set as text.

Update UserTransformOnRepresentation test to test text sources in batch
mode.

Change-Id: I049a6b94df8e3010d3eda8c31afa6b433362e7ad
Fixing Catalyst for the programmable filter.

The programmable filter can have '\n' in the script section
strings and this was causing problems. This converts the '\n'
to a '\\n' in the script that is run so that users can use
programmable filters the way they normally do in ParaView.

Change-Id: Ia4779fdbb5d233a161821053888c8ac03bc46e46
Fixed copy/paste errors in API documentation
Implemented feature request #10643 (allow legend font editing)

Change-Id: I41a599644f086332e5369dae3bd5281458fc8fad
Swap ports used by firefox and chrome web-based tests.

Change-Id: I295bc8653eb6db2beedf4180ec3ad6f85e8c0094
Fixed Windows build error.

Change-Id: I46748d208b8a45f6778b6e0ea3c54a999577eaa6
Get rid of compiler warning.

Change-Id: Ie0c1acdd5b967653d0e600665c5f55dfae25e4a3
Adding a Catalyst test for ProgrammableFilter.

Change-Id: Id2a17eab6544fdc9056e13b031b84c19c2a6908c
Fixing a compiler warning.

Change-Id: I5417c0a8d383a0c0649a6795d34a0fac70ec881f
Expose SetComputeTolerance and Tolerance for vtkPProbeFilter

Change-Id: If67ec050b6906a79e694ce82811cd1d8e748ee73
Use VTK's 'FIX: Get rid of dependent properties.'

Change-Id: Iee582aa947b9d5d16f2fd52c4c095382cce4e590
Mostly just re-arranging guides in groups, but also updating more text.

Added new information about graphics on Ubuntu 14.04 EC2 instances,
also added a new guide highlighting some of the existing pvweb
applications, put this new guide into a new section called Sample
Applications.  Fixed up some of the Apache as a front end text as
well.

Change-Id: Id6e79c308d63414379779e4a9d5e3419de9ffb99
Merge topic '10643_chart_legend_properties'

21808c43 Implemented feature request #10643 (allow legend font editing)
0e6d8f5f Fixed copy/paste errors in API documentation
Merge topic '13139-plot-small-geometry'

a0861b41 Use VTK's 'FIX: Get rid of dependent properties.'
5a7a5d52 Expose SetComputeTolerance and Tolerance for vtkPProbeFilter
Merge topic '14931-cluttered-histogram'

65ac40d4 Add an 'CalculateAverages' to XYHistogram test.
05ce7d45 Fix 14931: The Histogram filter does not Calculate Averages by default.