docs: wrote volumina intro
docs: intro to pixelpipeline
docs: small intro to the volume editor
docs: restructed into high level and low level parts
dialog title
fix ilastik issue 656
more verbose asserts
hitWidget can be None
progress dialogue improvements
disable prefetching
LazyflowSource: Removed __del__ method.
export widgets: Check for hdf5 dataset name before allowing the user to hit 'OK'
NavigationController: Don't handle scroll wheel events if the view isn't enabled.
widgets: export: Added basic dvid support, but with rough edges.
dvid export ui: cleanups.
ShortcutManager: Purge old shortcuts from the list after they or their targets have been deleted.
TODO: This should really be fixed by refactoring the shortcut management system.
Applets or workflows should be allowed to delete entire groups of shortcuts during their cleanup process.
layerwidget: Fixed manual quicktest.
bring back Viewer.title property
quadsplitter: Remove unecessary widget
Added volumina.NO3D flag, which allows clients to disable 3D support for testing purposes.
If volumina.NO3D flag == True, VTK is not even imported.