Add missing includes and forward declarations

I looped over the toplevel header files, creating a temporary two-line C
program for each consisting of
  #include "git-compat-util.h"
  #include $HEADER
This patch is the result of manually fixing errors in compiling those
tiny programs.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/branch.h b/branch.h
index 473d0a93e9..7d9b330eba 100644
--- a/branch.h
+++ b/branch.h
@@ -1,6 +1,8 @@
 #ifndef BRANCH_H
 #define BRANCH_H
 
+struct strbuf;
+
 /* Functions for acting on the information about branches. */
 
 /*