sg/commit-graph-cleanups (was Re: What's cooking in git.git (Jul 2020, #01; Mon, 6))

> * ds/commit-graph-bloom-updates (2020-07-01) 10 commits
>   (merged to 'next' on 2020-07-06 at 177e6b362e)
>  + commit-graph: check all leading directories in changed path Bloom filters
>  + revision: empty pathspecs should not use Bloom filters
>  + revision.c: fix whitespace
>  + commit-graph: check chunk sizes after writing
>  + commit-graph: simplify chunk writes into loop
>  + commit-graph: unify the signatures of all write_graph_chunk_*() functions
>  + commit-graph: persist existence of changed-paths
>  + bloom: fix logic in get_bloom_filter()
>  + commit-graph: change test to die on parse, not load
>  + commit-graph: place bloom_settings in context
>  (this branch uses sg/commit-graph-cleanups.)
> 
>  Updates to the changed-paths bloom filter.
> 
>  Will merge to 'master'.
> 
> * sg/commit-graph-cleanups (2020-06-08) 10 commits
>  + commit-graph: simplify write_commit_graph_file() #2
>  + commit-graph: simplify write_commit_graph_file() #1
>  + commit-graph: simplify parse_commit_graph() #2
>  + commit-graph: simplify parse_commit_graph() #1
>  + commit-graph: clean up #includes
>  + diff.h: drop diff_tree_oid() & friends' return value
>  + commit-slab: add a function to deep free entries on the slab
>  + commit-graph-format.txt: all multi-byte numbers are in network byte order
>  + commit-graph: fix parsing the Chunk Lookup table
>  + tree-walk.c: don't match submodule entries for 'submod/anything'
>  (this branch is used by ds/commit-graph-bloom-updates.)
> 
>  The changed-path Bloom filter is improved using ideas from an
>  independent implementation.
> 
>  Under review.
>  cf. <20200627155610.GN2898@szeder.dev>
>  cf. <20200627163335.GO2898@szeder.dev>
>  cf. <20200627155348.GM2898@szeder.dev>