* Numerous performance & stability improvements

* The Output block now has an out port which provides the rendered image for further processing
* Some data conversion fixes

* Improved drag handle placement in rectangular in-place editors

* Properties are more dynamic now

* Some changes to work with Qt 5.11

* Improved the IE cursors to work better on a black background

* Added an Erode block

* Added a Sharpen block
* The block list now shows a scrollbar if needed
* Fixed vertical resizing issues with the IE control bar

* Added helper classes to make working with color and grayscale pixels easier

* The Merge Channels block now checks for equal input dimensions

* Layers now have an opacity value

* Loading a project while an image editor is open caused a crash

* Added a preliminary Normalize block
* Some cleanup, fixing & refactoring

* Fixed the rubber band not disappearing when using the eraser tool