Implement a widget based view of the current sheet.
Allow adding a text replacement for freeform fields.
Put text replacements into the report (reportlab)

There are two new options. These allow suppressing the images (for privacy
reasons) or suppressig the text substitution which is prefered.
New utils package which contain utility functions. And some cleanups.

This is only a cleanup commit. Code is moved into a new utilities package,
and some unused code is dropped.
Remove bogus \offinterlineskip
Add freefromtext command for string replacements.
Output text from string replacements in LaTeX based reports.
Merge branch 'widget_view' (fixes #14)

Merge the widget_view branch which also allows freeform fields to be
manually replaced with strings.