Implemented handling of "copy tags from previous image" regarding positionable tags
Set the "dirty" flag in the setTaggedAreas function
Changed the in-memory storage format for positioned tags to something more convenient
Added a checkable button to show/hide all areas to ImagePreviewWidget. Added the infrastructure to disable area creation to ImagePreview.
Disable area display/creation if Dialog is not in InputSingleImageConfigMode
Fixed the last two commits.
Removed ImageInfo::setTaggedAreas in favor of using ImageInfo::setCategoryInfo.
Remove some unneeded calls to QString::fromLatin1.
Change signal/slot setup for showAreas.
Fix ImageInfo part of positionable tags.
Simplify AnnotationDialog::Dialog::slotCopyPrevious a little.
Further simplification.
Fix error in addCategoryInfo.
Code cleanup.