revlog: document that mmap resources are released implicitly by GC
It's okay-ish, but currently the open fd and the mapping itself are leaked
until the indexdata is deallocated. If revlog had close(), the underlying
resources should be closed there as well, but AFAIK there's no such hook
point.
ui: proxy protect/restorestdio() calls to update internal flag
It should be better to manage the redirection flag solely by the ui class.
ui: move protectedstdio() context manager from procutil
This is a follow-up series for
23a00bc90a3c, "chgserver: do not send system()
back to client if stdio redirected." The function is renamed using ui terms.