Merge branch 'jk/alt-odb-cleanup'

Codepaths involved in interacting alternate object store have been cleaned up. * jk/alt-odb-cleanup: alternates: use fspathcmp to detect duplicates sha1_file: always allow relative paths to alternates count-objects: report alternates via verbose mode fill_sha1_file: write into a strbuf alternates: store scratch buffer as strbuf fill_sha1_file: write "boring" characters alternates: use a separate scratch space alternates: encapsulate alt->base munging alternates: provide helper for allocating alternate alternates: provide helper for adding to alternates list link_alt_odb_entry: refactor string handling link_alt_odb_entry: handle normalize_path errors t5613: clarify "too deep" recursion tests t5613: do not chdir in main process t5613: whitespace/style cleanups t5613: use test_must_fail t5613: drop test_valid_repo function t5613: drop reachable_via function