histedit: integrate action class into flow This takes the newly added histeditaction class and integrates it into the histedit run and bootstrapcontinue logic. No actions implement the class yet, but they will be add in upcoming patches.

histedit: add a new histeditaction class This adds a new class called histeditaction. It represents a single action in a histedit plan. Future patches will integrate it into the histedit flow, then convert each existing action in to the class form one by one. This is part of a larger refactor aimed at increasing histedit robustness, maintainability, and extensibility.

histedit: allow histedit --continue when not on a descendant (BC) Previously we would not allow --continue if the current working copy parent was not a descendant of the commit produced by the previous histedit step. There's nothing really blocking us from continuing the histedit in this situation, so let's stop aborting in this case. This is technically a BC change, but it is making things more forgiving so I think it's ok. In the future we will likely add an 'exec' action to histedit, which means the user can do whatever they want during the middle of a histedit (like perhaps calling 'hg update'), which means we'll need to support this case eventually anyway.

tags: explicitly log which tags cache file is being written We now have multiple tags cache files. Record exactly which file is being written. This should help aid debugging into performance issues with any single filter.