CEGUI Imageset Exporter (Script-Fu)

;Copyright (c) 2008 Anton Lopatin
;
; DESCRIPTION:
; this script will create a .imageset definition file, each visible layer will be treated as a separate image and exported
; then the script will create a duplicate image, merge it down, and save with provided filename (and extension).
;
; INSTALL:
; copy to ~/.gimp /scripts/
; refresh scripts (Gimp->Extras->Script-Fu-> Refresh)
;
; USAGE:
; make sure your image is of the size 2^n
; click Export -> CEGUI Imageset ( Found in the top image menu)
; make sure that the output path ends with a slash