If timing between keys is less than (by default) 1 millisecond, assume
the text is being pasted. assume-paste-time option changes the value (0
disables). Based on a diff from Marcin Kulik.
Implement ECH (erase character, CSI X). Reported by Christian Neukirchen.
Remove the layout undo/redo code which never really worked.
Merge branch 'obsd-master'