#41 comma-separated E-mails in ContactEditor
 #41 added a field typeTaggroup to BasicPropertiesPanel

The field typeTaggroup has to be set in the constructor of
BasicPropertiesPanel. It determines the taggroup of the tags which are
filled into the Combobox Type.
 #41 set title of ContactEditor-dialog
 #41 description area of ContactEditor should not shrink
 #41 avoid StringIndexOutOfBoundsException on download

In the RepresentationRenderer a StringIndexOutOfBoundsException could be
thrown, if the filename had no period. This is avoided by using the
FilenameUtils.
 #41 show default title for ShowEditorInDialog
 #41 show default title for ShowEditorInDialog
 #41 after drag&dro show resource in RelationshipEditor
 #41 created a non modal version of ShowEditorInDialog

A non modal version of ShowEditorInDialog is needed, which behaves
differently from its parent class, because in the non-modal case
showDialog() returns immediately. Therefore the non-modal version needs
to inform its listeners if it changes were saved successfully. This is
not needed in the modal version as the program runs sequentially.
 #41 select the newly created tag via the index

In CreateNewTagAction the newly created tag has to be selected in the
combobox via the method setSelectedIndex(), because for some reason
the binding does not work with the method setSelectedItem().
 #41 avoid a ArrayIndexOutOfBoundsException

Avoid a ArrayIndexOutOfBoundsException in ImageGetterUtils
 #41 Content and Content location can be shown both

In the MetadataRenderer the download hyper link was not visible if the
content textarea was filled. Those two elements should be shown
independently from each other.