52ae67d659
In version 2 of block image diffs, we support a new command to load data from the image and store it in the "stash table" and then subsequently use entries in the stash table to fill in missing bits of source data we're not allowed to read when doing move/bsdiff/imgdiff commands. This leads to smaller update packages because we can break cycles in the ordering of how pieces are updated by storing data away and using it later, rather than not using the data as input to the patch system at all. This comes at the cost of the RAM or scratch disk needed to store the data. The implementation is backwards compatible; it can still handle the existing version 1 of the transfer file format. Change-Id: I7fafe741d86b92d82d46feb2939ecf5a3890dc64