changegroup: pass all state into group() This will allow us to split it into a standalone function. Differential Revision: https://phab.mercurial-scm.org/D4205

changegroup: inline _prune() into call sites The functionality is pretty simple. As a bonus, _prune() had special code for the manifest case. We can now exclude this check from the file call site. Differential Revision: https://phab.mercurial-scm.org/D4199

changegroup: inline _packmanifests() into generatemanifests() It is relatively small. Every other generate*() calls group() directly. So the new code is consistent. Differential Revision: https://phab.mercurial-scm.org/D4198