• fix grid static: true to no longer add any drag&drop (even disabled) which should speed things up, and setStatic(T/F) will now correctly add it back/delete for items that need it only.
  Also fixed JQ draggable warning if not initialized first #858
• add addWidget(opt) now handles just passing a GridStackWidget which creates the default divs, simplifying your code. Old API still supported.
• add save(saveContent = true) now lets you optionally save the HTML content in the node property, with load() restoring it #1418
• add GridStackWidget.content now lets you add any HTML content when calling load()/save() or addWidget() #1418
• add ColumnOptions to column(n, options) for multiple re-layout options, including 'none' that will preserve the x and width, until out of bound/overlap #1338
  including a custom function for you to create the new layout #1332