Various VTK-web improvement

- Improve workbench layout
- Prevent WAMP to automatically reconnect
- Fix PVWeb Catalyst widget prop ordering + spacing

Change-Id: Id15510d9ba595fc6e26c10196dcf0f28fcba415d
Merge topic 'vtkweb-improvement' into master

c3957363 Various VTK-web improvement
ENH: Coverage for MultiThreshold.

Add a Unit Test for vtkMultiThreshold. This filter was not being
tested at all. During the validaiton of test results an error was
detected in the XOR boolean operation. The error is also corrected
in the patch.

Change-Id: I4b8b53d602f0af48b3e93c1504220006e94418e4
Merge topic 'Coverage_MultiThreshold' into master

f3311d5c ENH: Coverage for MultiThreshold.
Add error function to vtk:mouseInteraction RPC

Display errors to the console rather than swallowing them.

Change-Id: I419147d7f8420046db7fb9b54035444285c99787
Merge topic 'vtkweb-error-handling' into master

fa652b66 Add error function to vtk:mouseInteraction RPC
Fix vtkweb catalyst css

Change-Id: I9150e6a09c0ff6bda8355e4d84a281eb98394635
Merge topic 'vtkweb-improvement' into master

a8f89050 Fix vtkweb catalyst css