Merge branch 'jk/format-patch-am'

* jk/format-patch-am:
format-patch: preserve subject newlines with -k
clean up calling conventions for pretty.c functions
pretty: add pp_commit_easy function for simple callers
mailinfo: always clean up rfc822 header folding
t: test subject handling in format-patch / am pipeline

Conflicts:
builtin/branch.c
builtin/log.c
commit.h