Use the correct preprocess function to add the modal administration

[argiepiano]

This relates to #91 - specifically see my comment #91 (comment)

Preprocessing of Entity Plus entities is confusing. One would logically assume that the following preprocess hook would work: template_preprocess_paragraphs_item() to preprocess paragraph items. But no. These preprocessing functions never get called. Which is what led people to use #theme_wrappers (to force that hook to run, but caused other issues). This also led a previous PR to use paragraphs_preprocess() to add the modal classes. Instead, you must use hook_preprocess_entity_plus and use if statements to check that you are preprocessing the right template/entity.

I will submit a PR in a minute.

IMPORTANT. For the PR to work you must:

• Remove this line: here..
• Apply the modification to the template to use array_classes done in Use $classes_array instead of $classes to apply css classes Use $classes_array instead of $classes to apply css classes #109

[argiepiano]

PR #111

Please test