This also works around the bug in GTK in its file system tracking/file
open dialog that causes a crash when a file (in a directory it is tracking,
such as the previous directry where an STL was sliced from) is modified
with vim.
Steps to reproduce the bug:
1) Slice a file from the GUI
2) vim test.stl in the same directory
3) i hello ESC ZZ
4) if Slic3r didn't crash to a gtk assertion failure, jump to step 2
5) if still no luck, your gtk isn't broken. What version do you have?-)