Add left and right margin setting command. When combined with top and
bottom margin, you can now create a completely separate sub-window. This command replaces CSI s to save the cursor position... since this non-standard extension is very widely used, set left/right margin only works when mode 69 is enabled using CSI ? 69 h. The margins are retained when CSI ? 69 l is sent, only the command to adjust them is disabled.
Showing with 689 additions and 380 deletions