* app/fileops_cmds.c
* tools/pdbgen/pdb/fileops.pdb: don't add an already registered
load|save handler twice to the list. This fixes the problem
that extension were listed twice if a load|save plugin changed.
* app/plug_in.[ch]: code cleanup, indentation
* app/xcf.[ch]: same here, include copyright headers
* plug-ins/common/wmf.c: properly cancel the load if the user
pressed Cancel in the dialog (fixes bug #6500)
--Sven