This patch moves rerere()-related functions into a newly created
The setup_rerere() function is needed by both rerere() and cmd_rerere(),
so this function is moved to rerere.c and declared non-static (and "extern")
in newly created rerere.h file.
Signed-off-by: Stephan Beyer <email@example.com>
Signed-off-by: Junio C Hamano <firstname.lastname@example.org>