#103 set property if import button was pressed

In BasicImportDocumentVisualPanel a property is set in the wizard if the
import button was pressed.
 #103 change the appearance of representation panel

The appearance of RepresentationsDataAccessInformationVisualPanel is
changed if the import button was pressed previously. Therefore the old
preoperties and methods were renamed as they were used to indicate if
the import panel was opened.
 #103 set property for relationship import button

A property is set to true if the import button was pressed in the
RelationshipsImportDocumentPanel component.
 #103 set property on meta data import
 #103 setting the property did not work

Setting the import-button-pressed property did not work properly for the
meta data.
Merge branch 'bug/103-enable-content-in-wizard' into dev