OpDataExport: Avoid a graph cycle caused by connection of OpDataExport.Dirty to a child operator.
DatSelection: Fix a warning message.
Make a few gui-created helper operators *siblings* to the applet top-level operator, not children of it, to avoid cycles in the graph (not strictly required, but useful for debug purposes).
DataExport: Fixed a potential secondary error that can happen when formatting an error message.
DatasetInfoEditorWidget: Fix #720
DataSelection: Don't require data to be on the same drive as the project file.
setup_mac.py: Added a hack to include the full git repo directories in the final distribution, to make it easier to update the source without redownloading the full binary.