repository: remove unnecessary include of path.h

This also made it clear that several .c files that depended upon path.h
were missing a #include for it; add the missing includes while at it.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/ls-tree.c b/builtin/ls-tree.c
index f4331c6..c06858d 100644
--- a/builtin/ls-tree.c
+++ b/builtin/ls-tree.c
@@ -12,6 +12,7 @@
 #include "blob.h"
 #include "tree.h"
 #include "commit.h"
+#include "path.h"
 #include "quote.h"
 #include "parse-options.h"
 #include "pathspec.h"