ref #7010 Adapt media view handlers for multiple selection

avoid widgetIsDisposed exceptions by check of control is disposed

cherry-pick from hotfix

ref #7056: add possibility to show preview of the image in media view

Merge branch 'develop' into bulkEditorE4

Conflicts:¶

eu.etaxonomy.taxeditor.editor/META-INF/MANIFEST.MF¶

eu.etaxonomy.taxeditor.editor/src/main/java/eu/etaxonomy/taxeditor/editor/view/concept/e4/ConceptViewPartE4.java¶

eu.etaxonomy.taxeditor.editor/src/main/java/eu/etaxonomy/taxeditor/editor/view/descriptive/e4/FactualDataPartE4.java...¶

ref #6925 Pull up selection handler and service

ref #6911, #6925 Clear views when selection providing editor is closed

ref #6906 fix selection handling

ref #6595 removed e3 name editor classes (unstable navigator plugin)

Merge branch 'develop' into nameEditorE4