New features:
- the BatchMode flag is a progressbar suppressor flag now for the import/export plugins to avoid parallel progressbar usage
- better progressbar support for the csv import/export plugins and for the animation sequence import/export (with cancel)
- a new cancel button added to the progressbar
- new functions for KisDocument() to create correct progressbar environment for file import/export
todo: a new error message type for the canceled file operations (now cancels with OK).