Remove old import statement from Python tests.

The "cgmsmtk" module no longer exists because it was a hack.
Now "import smtk" will also import CGM if the CGM module exists.
Be consistent about returning stuff in "entities".

Do not define "bodies" as an item in any operator's results.
Merge topic 'fix-cgm-ops'

aa38d169 Be consistent about returning stuff in "entities".
d83c9e11 Remove old import statement from Python tests.
c8e7f0c1 Remove ambiguous return value in BooleanUnion result.
Fix stupid-bad table formatting in docs.

This fixes things so that

1. Table columns are not impossibly wide due to the "responsive"
   design. Now users do not have to scroll horizontally to view
   all the text in a table row.

2. Paragraphs in tables have a small bottom border that makes
   intentional breaks less cluttered.
Merge topic 'doc-table-width'

e8e8efdf Fix stupid-bad table formatting in docs.