Setup a project with Perforce support.
Open some file in your perforce client area.
Select "Version Control -> Delete".
The file is removed from the filesystem, but it remains open in slick.
In Slick, select File->Save.
Slick pops an erroor complaining that the file is ReadOnly .... but the file doesn't exist in the filesystem.
Switch away from slick and come back, then slick prompts for what to do with the missing file.
Seems like VCS->Delete should close the buffer too.
