fixed edit of reference column was losing target sheet
added Color column type support
integrated level editor (allow both color and image based layers)
added alpha/visible layer options
support for layers at runtime
visible feedback in ui
ensure that moving data order keep layers data safe
added game objects layers
handle properties edition for game objects layers
minor ui fixes
allow object layers with no id (parametrize color)
added width/height zones, allow grid lock
added TFile support + img preview
documentation, tile size change, handle resize when change with/height
added level background image
small fixes for File handling
added TTilePos, moved types from Module to Types
support for TTilePos in level display
fixes for level loading / tilepos
added TTileLayer, review image handling, pixel zoom