Color overlay updates
An update for the color overlay feature:
- Remove the dedicated icon/button from the layers docker.
- Add the same action to the Add/+ button menu and the right-click popup menus.
- Replace the action icon with the new one contributed by Sake (from KA).
Regarding the removal of the button. It is a hotly debated issue, with strong opinions from both sides. Some people think the icon is very important, others think it's unnecessary and distracting.
Looks like either way someone will be disappointed about it. I decided to remove it for the following reasons:
- Krita interface tends to be minimal rather than having a lot of buttons.
- There are other more frequently used features that don't have a dedicated button in the layers docker (example: group layers).