I posted this on GitHub before I saw that you don't accept pull requests there, so here it is:
Changes to FileBasedDocument
- send changed() when file name is updated
Changes to Plug-in Host:
- Add new document command
- Save open/closed state of each type of plug-in windows
- Save position for each type of plug-in window
- Open last used file on program launch
- Add current file name to application title bar
- Add command to bring all plug-in windows to front
Code in dropbox: https://www.dropbox.com/s/4by7l7juztd0vgd/pluginhost.zip?dl=0
