revlog: postprocess chunk to slice them down to a certain size After the density slicing is done, we enforce a maximum chunk size to avoid memory consumption issue.

revlog: add function to slice chunk down to a given size It is possible to encounter situations where the slicing based on density did not achieve chunk smaller than the 4*textlength limit. To avoid extra memory consumption in those cases, we need to be able to break down chunk to a given size. Actual caller comes in the next changesets.

revlog: extract density based slicing into its own function We are going to introduce another slicing step. We start by extracting the existing one into its own function.