Trace Draw 4+

Fix issue where image is not loaded from saved project.
Fix issue with screenshot in color picker tool not displaying properly when alpha is reduced below 1.
Added a web view to display instructions website.
Fix issue where gradient swatch is not updated if colors are changes.
When adding a new layer, it is now added above the active layer.
Previously when setting a secondary color a gradient was drawn only when drawing an open curve. Now it is drawn for a closed curve as well.
Fixed bug where curve edits were not reflected in the project after leaving the edit screen.
Fix an issue where there is no image to start the project.
The existence of a secondary color is what makes a curve have a gradient. So the secondary color is now cleared when selecting a new primary color. This way closed, open, and gradient curves can be combined on the same layer.
Fixed an issue where open curves are drawn when the open/closed tool is set to closed.
Added zoom reset feature on Mac. ⌘0
Zoom button removed from Mac version.
Display an alert if the dropper tool is used when there is no image.
Pinch gesture disabled for Mac version. Mac users should use command +/-/0 instead or the menu.
Dots are now redisplayed after zooming using the keyboard.