4.5.0

1. Zooming with mouse wheel
2. Context menus for many different objects attributes are provided
3. Context menu for every drawn object can be activated via toolbar button
4. Support browsing of TTask and derived classes (#40)
5. Apply user range for drawing TH1/TH2 histograms, also when superimposed (#44)
6. Implement scaling factor like x10^3 on the vertical axes
7. Provide shortcut buttons for each subpad
8. Implement simple drawing for TBox, TWbox, TSliderBox classes