Simply changing is opacity is nice, but does not work well when the
board contains more tasks then fit on the screen.
Moreover, moving tasks now properly handles in controller/model, so it
is possible to show only some tasks.
- Project > Edit Board and Project Summary pages now show description as tooltip.
- Project > Edit Board shows textarea with markdown preview. Edit column also shows markdown preview.
- Fixed bug while adding a new column inserts description as column limit.
