The checksum-stream being situated in front of the block-stream, which
ensures block size alignment to multiples of 512, and pads the last block,
caused the checksum to be incorrectly calculated for images where the last
block needed to be padded.
Change-Type: patch
This implements a new way of image write streaming under use of pipage and blockmap, which paves the way for a few things like using network locations as sources, and imaging of storage devices (aka backups). As it allows for mutation of the streaming pipeline while it's writing, it also facilitates the development of dynamic block-mapping.
Change-Type: minor
