Fixed some unintuitive behaviour in `Transformer.{cut,copy}`.
Fixed some unintuitive behaviour in `Transformer.{cut,copy}`.

The old behaviour was to copy all selected events in the stream before passing
to the next transform. The new behaviour is to copy only a single contiguous
block before yielding to the next trasnform.

The previous behaviour can be preserved with the following construct:
    `...copy(buffer, accumulate=True).buffer()...`


git-svn-id: 35afe1d183cbd4849519a30d21151995795e8f1d@858 de761a21-4c15-0410-92fa-db90950b6ec0

dag/genshi,dag/genshi,davidfraser/genshi,davidfraser/genshi,dag/genshi,davidfraser/genshi,davidfraser/genshi,dag/genshi