fix Dialog show/hide when duration==0, fixes #16790 !strict
Fixes #16743.  If a search is already in progress, stop SPACE on keydown and process in keypress.
Update util/less to v1.3.3, and use svn:external to pull in code rather than copying the files, refs #12099.  Note that the svn:external points to the v1.3.3 tag (which is the latest tag at this time), not to trunk.