Merge branch 'lt/rev-list' into next

Merge branch 'lt/rev-list' into next

* lt/rev-list:
  Rip out merge-order and make "git log <paths>..." work again.
  Tie it all together: "git log"
  Introduce trivial new pager.c helper infrastructure
  git-rev-list libification: rev-list walking

blame.c #include's epoch.h; it needed to be killed.