largefile: use `parentchange` during rollback rollback is updating parent without touching the working copy. It should wrapped in a `parentchange` context. Differential Revision: https://phab.mercurial-scm.org/D11108

largefile: consider `updatelfiles` as a `parentchange` This is not strictly a `parentchange`, however this is still some internal dirstate adjustment as "similar" enough that it seems find to do so. Differential Revision: https://phab.mercurial-scm.org/D11107

largefile: use `set_tracked` in the `hg copy` overwrite This is the new shiny API. Differential Revision: https://phab.mercurial-scm.org/D11106