def mouseReleaseEvent(self,e):
        if (e.button()==QtCore.Qt.LeftButton or
            e.button()==QtCore.Qt.RightButton):
            self.dragging = False
endpoint to power the calendar heatmap on the welcome page
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/packages/spreadsheet/spreadsheet_helpers.py/CellResizer.mouseReleaseEvent--crossover with--dataset/ETHPy150Open airbnb/caravel/caravel/views.py/Caravel.activity_per_day