renamed directories from plural to singular (Views->View, Utils->Util, etc etc)
made GUI/Model independent of GUI/View
organized GUI/Model into subdirectories
moved GUI/main to App
moved files from GUI/View to GUI/View/Toplevel
broke most cyclic dependences between subdirectories of GUI/View (the remaining ones are mostly for calling functions from ProjectManager that should be moved down to ProjectDocument)
obtained two subdirectories of GUI/Model with non-cyclic dependences (Component, IO); all other subdirectories still forming a big interdependent cluster
removed some unused source files
removed numerous unneeded includes
corrected a few relative include paths
splitted several source pairs into two pairs
splitted class Application into two (ApplicationSettings vs SessionData)
renamed many namespaces
shuffled code in several functions to treat anomalous conditions first; no else after return
substituted QWidget::parentWidget for m_mainWindow and other self-made solutions
converted SavePlotAssistant from class to namespace
moved some enum definitions to low-level file ID.h