Various small code improvements
Added AnalysisTab class docstring
Added automatic Angular viewport swap on file load
Viewport name fix
Fixed mouse cursor glitch in PixelSelectOverlay
Added small diagram illustrating OdemisGUI's startup sequence
Fixed bug in Stream test module
Spatial Spectrum Viewport has been linked to the line select tool
Extended the TupleVa to also allow itself to be set to None instead of just Tuples.

The default value of the TupleVA was already None. This did not cause problems, because the Tuple check was not performed when the value was set in the class' constructor.
GUI: Small SpatialSpectrumViewport updates
GUI: Added origin ticks to Axis legend
Legend range bug fix
Retry to reach the lens aligned position anyway
Added MarkLine overlay to OneDimensionalSpatialSpectrumCanvas
Extended docstrings with information on the focussedView and viewLayout Vigilant attributes
Grid bug search *wip*
GUI grid focus fix
GUI: Reworked the ViewportGrid so the Show and Hide methods on the Viewports can be called after the size calculations instead of before, in hopes of resolving the white flicker when switching viewports.
GUI: Final fix for grid bug (background flicker)
GUI: Fixed an issue with the small Message dialogs, where they would not (completely) display when are invoked right before a ong running and blocking task