• package is now ES2020 (TS exported files), webpack all.js still umd (better than commonjs for browsers), still have es5/ files unchanged (for now)
• optimize #2243 removed gs-min|max_w|h attribute generated in CSS or written out as they are never used for rendering, only for initial load. This reduce our column/row CSS in half!
• optimize: removed gs-w='1' and gs-h='1' dom attribute writing since we already have min-width/min-height set, no need to set more attributes.
• optimize: remove 'ui-draggable' and 'ui-resizable' since wasn't used in CSS and we have the -disabled version when off (so we can use not(xyz-disabled)).
• add: GridStack.saveCB global callback for each item during save so app can insert any custom data before serializing it. save() can now be passed optional callback
• move: GridStack.addRemoveCB is now global instead of grid option. load() can still be passed different optional callback
• fix: addGrid() to handle passing an existing initialized grid already
• break: GridStackOptions.subGrid -> GridStackOptions.subGridOpts. We now have GridStackWidget.subGridOpts vs GridStackNode.subGrid (subclass) rather than try to merge the two at runtime since very different types...
• tons of improvements for Angular wrapper - now shipped!