updated for version 7.3.862
Problem:    Dragging the status line can be slow.
Solution:   Look ahead and drop the drag event if there is a next one.
Added tag v7-3-862 for changeset dd4f3ceb5d86
updated for version 7.3.863
Problem:    Problem with 'ambiwidth' detection for ANSI terminal.
Solution:   Work around not recognizing a term response. (Hayaki Saito)
Added tag v7-3-863 for changeset 5c0652f455c9