Make the exclude-button to an include-button
Make the columns with properties scale with the dialog-window
Removes the dummy-text in fields for pre-view the properties and make
them unselected if no file with properties is loaded
Make so no error-message is visibly when open the dialog and fixes the
with of the header combobox
Merge pull request #24 from KlasJoenssson/Bug3481

Some fixes in the add prop. to sdf wizard