b4 v0.15.2 released

Hi, all:

B4 v0.15.2 is now available with bug fixes for the review TUI and mbox
parsing. There won't be many more updates to the 0.15 stable branch, because
the master is diverging rapidly and backporting fixes is becoming challenging.

Upgrade using your usual mechanism:

    pipx upgrade b4

New feature (introduced in response to a bugfix):

- review: show visual cue for patches unchanged between revisions --
  when upgrading a series, identical patches now display a dim "≡"
  marker so you can focus your review on patches that actually changed

Bug fixes:

- review: prevent double-sending of reviews carried over from a prior
  revision after a series upgrade
- review: fix crash when stored message-id points to wrong version
  thread after a series upgrade
- review: fix IndexError crash when toggling followups
- review: fix crash when background rescan completes while a modal
  screen is active
- review: fix replies to additional patches being treated as inline
  reviews on the wrong patch
- review: fix range-diff failing to find previous series revision
- review: fix upgrade branches polluting tracking DB with wrong
  change-id
- review: show per-series error details after "Update all" instead of
  only a total error count
- mbox: don't split on "---" in free-form reply messages (fixes body
  content being silently discarded when encountering a "---" marker)

Thanks to Mark Brown and Miroslav Benes for the bug reports.

Best regards,
-- 
KR