BUG #14148. Fix location of executable path.

When executable was run from PATH, we were not determining the executable path
correctly which was messing up the logic to find Python module paths. This fixes
that issue.

Change-Id: I1db76f3f5ca9b4e9b9de26f02584332689ef7632
Merge topic '14148_fix_path_issues' into next

de7bc24 BUG #14148. Fix location of executable path.
Allow data object to be NULL inside DataDeliveryManager

This can happen when the RequestData of an algorithm fails.

Change-Id: I899ef01ca4b22d568ad1fb6254cf9be124b81160
Merge topic 'allow_request_data_to_fail' into next

5b6122a Allow data object to be NULL inside DataDeliveryManager
Remove vtkPTableToStructuredGrid to use vtkTableToStructuredGrid instead

Change-Id: Ie2401485b43536a395dbc2c77145522aefbbc377
Add comment with more explaination

Change-Id: I7bea339670b7e61576e23c9fc3417ceae9399435
Merge topic 'table2structured_one_piece_extent_fix' into next

908d37b Add comment with more explaination
1281c9f Remove vtkPTableToStructuredGrid to use vtkTableToStructuredGrid instead
python -- assign lookup tables by name

Added a reader for ParaView's exported XML colormaps to simple.py.
With the reader one could load and assign loookup tables to arrays
by lookup table name. ParaView's default LUT's (in ColorMaps.xml)
are installed and loaded by default in the reader's constructor.

Change-Id: Idd35965518f38f89c2d71be03e5baf7f501e99d6
Merge topic 'simple-py-lookup-tables' into next

9c4f469 python -- assign lookup tables by name