tests/test-revlog-packentry.t

pull: call the `b2x-transactionclose` hook when closing the transaction

We need a wider set of hooks to process all the changes that happened during the
pull transaction. We reuse the experimental `b2x-transactionclose` hook set
from server's unbundle for consistency. This hook is experimental and will not
remains as-is forever, but this will open the door for experimentation in 3.2.

  $ hg init repo
  $ cd repo

  $ touch foo
  $ hg ci -Am 'add foo'
  adding foo

  $ hg up -C null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

this should be stored as a delta against rev 0

  $ echo foo bar baz > foo
  $ hg ci -Am 'add foo again'
  adding foo
  created new head

  $ hg debugindex foo
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       0  .....       0 b80de5d13875 000000000000 000000000000 (re)
       1         0      24  .....       1 0376abec49b8 000000000000 000000000000 (re)

  $ cd ..