z-index layers
convert range to Moment instances
rearrange layers
Schedule.refresh() speedup
cycle layers button works
classify items
iterate slice on layer items
no more .items, use .layers
add `cell min width` to settings
special click layer overlays background layers
docs
add .correctColumnWidth()
better mouse behavior
add .hasColumn()
adjust event XY for border size
css
update test
version 0.1.2