#955 Make the difference between different parts of data entry forms clear

[Ahasuerus]

Make the difference between different parts of data entry forms clear. In Import Content, add a sub-header between the "Import from a Publication" section and the "Import Individual Titles" section. Ditto the "Variant to an existing title" section and the "Variant to a New Title" section of the "Make Variant" form.

[Ahasuerus]

Implemented in:

edit/importcontent.py 1.10
edit/mkvariant.py 1.25

Installed in r2016-209 on 2016-12-17. Closing.