[PATCH v5 0/7] %(trailers) improvements in pretty format

Updates since v4:
 * Coding style fixes
 * Reuse git_parse_maybe_bool for bool parsing

Anders Waldenborg (7):
  doc: group pretty-format.txt placeholders descriptions
  pretty: Allow %(trailers) options with explicit value
  pretty: single return path in %(trailers) handling
  pretty: allow showing specific trailers
  pretty: add support for "valueonly" option in %(trailers)
  strbuf: separate callback for strbuf_expand:ing literals
  pretty: add support for separator option in %(trailers)

 Documentation/pretty-formats.txt | 260 ++++++++++++++++++-------------
 pretty.c                         | 113 +++++++++++---
 strbuf.c                         |  21 +++
 strbuf.h                         |   8 +
 t/t4205-log-pretty-formats.sh    | 117 ++++++++++++++
 trailer.c                        |  25 ++-
 trailer.h                        |   4 +
 7 files changed, 415 insertions(+), 133 deletions(-)