ImportModuleVersion stores the unitDefinitionType of the loaded unit
definition. During the initialization of the unit, the individual
elements can react to the stored value.

Fixed-width pages are always centered in the browser, even if the
specified percentage is not equal to 50%.

The percentage weighting of the pages has an effect if the width of the
pages is greater than the width of the browser window.

... a played audio file

When the user exits selecting between paragraphs, the offset of the
end container is set to 0. In Firefox this always (in Chrome sometimes)
leads to a misinterpretation of the selection. Therefore, the offset
is manipulated.

When the user finishes selecting between paragraphs and the selection
happens from back to front, Firefox does not consider the start
container as a selected child node. Therefore, it is added to the
list of selected nodes at the beginning.

Show warning messages of input fields at event 'NavigationDenied' only
if reason "responsesIncomplete" is sent

- Map value between unit state and element model
- Takes over methods that were previously present in element container
- Gets and holds a list for mapping drop list elements

This prevents the section from being placed in front of elements
with negative z-index

This reverts commit 87534c53.

The entire HTML is no longer saved, but only the indices and the color
of the markers

- Use the same default state for interactiveMuteControl
and for playerProps.interactiveMuteControl

- Ignore blank pages when calculating the response progress

- Use the same font properties for input element and button element
- Change cross out behaviour. The button now behaves as
toggle button and sets the focus to the input element only when it is
crossed through.