branchcache: have an explicit method to update the on disk cache Explicit is better and will give use more flexibility for future evolution of the storage.

crecord: drop calls to `curses.endwin()` We got a bug report where `curses.endwin()` failed with `_curses.error: endwin() returned ERR`. Looking at e306d552dfb12, it seems like we should be able to just remove these calls.

config: move the option to mmap rev branch cache in the storage section See previous commit for rational.