DataSelection: If the user selects a dataset that isn't valid for his workflow, automatically open the dataset property editor.
Resolves #433
OpThresholdTwoLevels: Output cache blockshape is only 1 pixel wide in the time dimension.
Fixes the second part of issue #416
adopted new calling convention for LabelImageViewerWorkflow init
fillmissing: added ui button, serializer, ... (beta)
Merge pull request #442 from burgerdev/pr-fillmissing-persistence

fillmissing: added ui button, serializer, ... (beta)
Temporary operator instances are always initialized with parent, not graph.
widgets.ViewerControls: Update for recent ExportDlg api change.
manual tracking: do not use op5ifyer
tidied up manual tracking
ProjectManager.createBlankProjectFile() now accepts optional kwargs for h5py.File; extended method documentation
removed stray print statement
DataSelection: Serializer: Provide graph arg to temp operators to avoid assert in unit tests.
PixelClassification: Serializer: Init temp ops with graph arg to avoid assert during unit tests.
tests: AppletSerializer: SerialDictSlot: Added a basic unit test while investigating #404.
(Wasn't able to reproduce.)
manual tracking: do not add multiple events for merged objects
shell.creatAndLoadNewProject(): passing thru h5 File parameters
chaingraph tracking: renamed thresholding applet
chaingraph tracking: force setValue for parameter dict slot, solves issue #404
chaingraph tracking: do not use op5ifyer
also obey data range settings from datainput applet for grayscale images