port from pd-l2ork git: 63d853e3343fe76ad7b06c5c239bf2af5f217bfc

*fixed bug reported by Liam Goodacre regarding donecanvasdialog causing parent patch to open in case subpatch's properties have been changes (e.g. via scripting). See http://disis.music.vt.edu/pipermail/l2ork-dev/2016-January/000810.html for more info.