Attempt to add YouTube embed handling, revise .webp support, support corrections in 1:1 DMs, and a whole load of other changes. Also bump version number to 3i and begin Indev phase

main.go

@@ -38,7 +38,7 @@ import (
 	// TODO: integrated theme switcher
 )
 
-var version string = "3.142a"
+var version string = "3i"
 var statBar widget.Label
 var chatInfo fyne.Container
 var chatSidebar fyne.Container