* "Undo(Redo) last brushstroke" -> "Undo(Redo)".
* Sync `_updateActionSensitivity` menu method with the new undo/redo behavior.
* Smooth button action is no longer destructive.
* Clean undone smooth transformations when doing a new smooth transformation.
With old GS/GJS, some GType names were generated from class names without sanitizing it (e.g. Menu.ActionButton).
Instead of defining all GType names, sanitize all class name as it was GType name, and let GJS generated GType name securely when it is necessary.
Fix#46.
* Take scale factor into account.
* Put it in '_onMenuOpenStateChanged' so the max-height will be updated if the monitor size change.
See PanelMenu.Button.
* A minimum width for the menu, the same as the aggregate menu, in order to prevent the menu with from growing on submenu open.
* A maximum width for uncontrolled content (font, image and drawing names). Same value and same reason.
* Style the font family labels in idle loop to open the submenu fastly.
* Add the drawing gicons in idle loop to open the submenu smoothly.
* Pass Clutter color and Pango fontDescription objects to elements, not strings.
* Do not use the color format '#rrggbbaa' in svg since it is not supported in GNOME 3.24.
* Let the user choose the directory.
* Rework of Files.Images.
* area.currentImage is now an ... image, not an index.
* Add 'switch-image-file-reverse' keybinding.
* Add image gicons (from thumbnails) in the submenu.
* Images are reset on drawing mode left or on images added from the clipboard.
Since the most drawing params can be changed via menu or shortcuts, remove default.css and user.css.
* Missing params like palettes, dash, grid, etc, are added to prefs.
* Add palette choice to menu and shortcuts.
* Some defaults like fonts, line width, etc, are no longer modifiable by the user.
abakkk