[Layout] Fix Exception: "actorData is not defined"
[a11y applet] Remove old code that causes runtime error.

    JS ERROR: !!!     message = '"this.emit is not a function"'
    JS ERROR: !!!   Exception was: TypeError: this.emit is not a function
    JS ERROR: !!!     lineNumber = '202'
    JS ERROR: !!!     fileName = '"/usr/share/cinnamon/applets/a11y@cinnamon.org/applet
Fix a regression caused by #1159, adresses #1502
Update files/usr/share/cinnamon/applets/sound@cinnamon.org/applet.js

Add "pithos" as a player compatible with the sound applet.
add a centralized method to create clones of a window and its transients, keeping their relative size to each other
change alttab with the option 'thumbnails', only accessible directly via gsettings, to displaying windows and their transients
[Expo] use createWindowclone function to show transients in overview mode.
[Scale] use createWindowclone function to show window with transients.
added option to include relative positions for clone scaling
added thumbnailing for transient windows
add positioned previews for transient windows
moved function createWindowClone from js/ui/windowManager.js to js/misc/windowutils.js
[windowUtils.js] s/c/actor/
[altTab.js] Fix missing variable declaration.
[Expo] Explicitly test overviewMode for false.

Since overviewMode is undefined to begin with, checking explicitly
for false will let the first call of setOverviewModeOff run without exiting prematurely.
[Scale] Fix initial-positioning regression
[DND] Cancel ongoing drag if we detect that Escape is pressed.
[Popup menu] Avoid closing menu if DND is in progress.
menu editor - remove separator button
Hide move up and move down buttons in cinnamon menu editor.

Remove settings tree from app sys, merge settings menu entries with
the applications menu, remove all cinnamon calls to settings tree.