I have extended the occur feature in Emacs to allow direct editing in
the *Occur* buffer by propagating the changes to the original buffers.

With the attached preliminary patch, one can press `C-x C-q' or `C-c
C-c' to enter occur-edit-mode and start editing. Pressing `C-x C-q' or
`C-c C-c' again finishes the edit.

Comments are highly welcomed. Thanks in advance.

Leo