Merge branch 'db/cover-letter'

* db/cover-letter: Improve collection of information for format-patch --cover-letter Add API access to shortlog t4014: Replace sed's non-standard 'Q' by standard 'q' Support a --cc=<email> option in format-patch Combine To: and Cc: headers Fix format.headers not ending with a newline Add tests for extra headers in format-patch Add a --cover-letter option to format-patch Export some email and pretty-printing functions Improve message-id generation flow control for format-patch Add more tests for format-patch Conflicts: builtin-log.c builtin-shortlog.c pretty.c