Icons most likely temporary. A bit problematic when the selection is in negative coords and the preview does not work well with mirroring and mirror view. Same is true for the shape tools.
When the user clicks on a pixel, all pixels of the same color are being selected. Shift adds to the selection, Ctrl subtracts. The icon and the hint tooltip are temporary.
Instead of having a gazillion icons for each tool and its blue-orange variations, which led us to create 4 different textures for each tool, now we only need one texture for each tool and each theme. The blue-orange background has been made into a different TextureRect for each button.
This makes it easier for people to create new tools. Now, each new tool requires 3 textures (to cover every theme), instead of 12(!). I'm hoping to bring the number down to 1 in a future commit, by automating the theme color converting process.
