• add #992 support dragging into and out of nested grids from parents! Thank you @arclogos132 for sponsoring it.
• add #1910 new column:'auto' option to size nested grids to their parent grid item column count, keeping items the same size inside and outside. Thank you @arclogos132 for also sponsoring it.
• fix #1902 nested.html: dragging between sub-grids show items clipped
• fix #1558 dragging between vertical grids causes too much growth, not follow mouse.
• fix #1912 no longer force rows for min-height
• fix #1888 locks up with nested grid when 'column' is set to 1