Moved scroll wheel handling to well log trace plot viewer, using event
filter for the plot canvas to get the mouse Y position, which is
transformed to the corresponding plot depth value and used as center for
zooming.
Cleaned up ownership in WellLog plot classes
initAfterRead() is implemented
moved code related to command features from the WellLog classes
Still plots are not redrawn/reloaded when opening a project file.
Traces can be added to and deleted from well log plots, and curves with
dummy data can be added and deleted. TODO: Replace dummy data with real
well log data and data extracted from the model.
Added command feature for adding new well log plots (right-click "Plots"
in the project tree view). Will create dummy Qwt widget added as an MDI
window.
TODO: Complete the relations between the entities, and add
properties/property editors. Create more advanced viewer widget for
plotting of multiple traces with multiple curves. Harmonize MDI stuff
with 3D viewers.
