Significant rename detection rewrite

This flips rename detection around so instead of creating a
forward mapping from deltas to possible rename targets, instead
it creates a reverse mapping, looking at possible targets and
trying to find a source that they could have been renamed or
copied from.  This is important because each output can only
have a single source, but a given source could map to multiple
outputs (in the form of COPIED records).

Additionally, this makes a couple of tweaks to the public rename
detection APIs, mostly renaming a couple of options that control
the behavior to make more sense and to be more like core Git.

I walked through the tests looking at the exact results and
updated the expectations based on what I saw.  The new code is
different from the old because it cannot give some nonsense
results (like A was renamed to both B and C) which were part of
the outputs previously.

1 files changed, 0 insertions, 1 deletions

diff --git a/tests-clar/object/raw/convert.c b/tests-clar/object/raw/convert.c
index 86f0d74a9..88b1380a4 100644
--- a/tests-clar/object/raw/convert.c
+++ b/tests-clar/object/raw/convert.c
@@ -87,7 +87,6 @@ void test_object_raw_convert__convert_oid_partially(void)
 	const char *exp = "16a0123456789abcdef4b775213c23a8bd74f5e0";
 	git_oid in;
 	char big[GIT_OID_HEXSZ + 1 + 3]; /* note + 4 => big buffer */
-	char *str;
 
 	cl_git_pass(git_oid_fromstr(&in, exp));