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.
* Import palettes from a .gpl file (one palette for each column).
* Add possibility to use more than 9 palettes.
* Color display names support.
* color.toJSON for svg and drawing saves, color.toString for display.
* Rename "Persistent" to "Persistent over restarts".
* If disabled, "Persistent over toggles" has priority over "Persistent over restarts" and "Drawing on the desktop".
Close issue #42.
Array is more semantically appropriate.
For example 2 actions may have the same translations (error of a translator). With an object (or a map), only the second would be displayed, which is problematic to alert to the problem.
Additionally, handle the case where some GSettings keybinding values are empty.
* 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.
* It is no longer required to clamp the setting value in area.js.
* Add a "range" property, completed with another 'step' property, to PixelSpinButton in order to directly initiate the lower and upper values of the adjustment from the relevant setting range.
* Not related: fix an inversion between Pango and Cairo in element.js.
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.
Keybinding to ungrab keyboard and mouse while drawing remains at the top.
To be aware that this create some problems with the shell (DnD #1 and maybe more ?).
related to #6, #9, #20, #24, #33
* `SCALE_PRESERVE` (preserve ratio)
* `SCALE` (vertical, horizontal or both)
There is a third transformation, `SCALE_ANGLE`, that is not used because it causes problems to the `elementFinder`. Probably a bug of Cairo.inStroke that do no consider scales.
* 'Shapes' -> 'Tools' ('Shapes' + 'Manipulations')
* 'TextState' -> 'TextStates'
* Rotation centers are now computed dynamically (when building Cairo or SVG paths).
* Text rotation center is now located at the beginning of the text.
* Text elements gain a 'lineIndex' attribute to retrieve the rotation center of the first line.
Pointer movement is ignored when the `space` key is held.
To ensure [Screenshot Tool](https://extensions.gnome.org/extension/1112/screenshot-tool/) extension compatibility, we need a way to let the third extension select the screenshot area with pointer but without leaving drawing mode and without drawing.
As a side effect, it allows to insert straight line segments in free drawing (after releasing the key).
Fixes issue #20