Issue 649: Improper cursor redraw for grid_scroll
Issue 649: Improper cursor redraw for grid_scroll

The cursor should be updated both before and after scroll events. One will
remove the old cursor and the other will draw the new cursor.

Without both draw events, the scrolloff setting can cause artifacts.

equalsraf/neovim-qt,equalsraf/neovim-qt,equalsraf/neovim-qt,equalsraf/neovim-qt