Most files under `git2/sys` have their includes prefixed with `git2`. Since Docurium exports its input headers in a temporary directory without the `git2` prefix, all those headers fail to parse.

Otherwise docurium/clang chokes on the types, and ignores the documentation comments altogether.

Worktrees can be made from bare repositories

We were previously conflating any error into GIT_ENOTFOUND, which might
or might not be correct. This fixes the code so a config error is
bubbled up, as well as preserving the semantics in the face of
worktree-repositories

docs: add documentation to state differences from the git cli

Sanitize the hunk header to ensure it contains UTF-8 valid data

The diff driver truncates the hunk header text to 80 bytes, which can truncate
4-byte Unicode characters and introduce garbage characters in the diff
output. This change sanitizes the hunk header before it is displayed.

This mirrors the test in git: https://github.com/git/git/blob/master/t/t4025-hunk-header.sh

Closes https://github.com/libgit2/rugged/issues/716

examples: ls-files: add ls-files to list paths in the index

OpenSSL legacy API cleanups

This is the "OpenSSL available" global init function after all

worktree:  add functions to get name and path

Fix deletion of unrelated branch on worktree

mbedTLS support

Configuration entry iteration in order

blame_git: fix coalescing step never being executed

Fix leaks in master

Leak fixes for v0.27.1

worktree: Read worktree specific reflog for HEAD

Valgrind log:

==2711== 305 (48 direct, 257 indirect) bytes in 1 blocks are definitely lost in loss record 576 of 624
==2711==    at 0x4C2CC70: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2711==    by 0x5E079E: git__calloc (util.h:99)
==2711==    by 0x5E0D21: open_worktree_dir (worktree.c:134)
==2711==    by 0x5E0F23: git_worktree_lookup (worktree.c:176)
==2711==    by 0x5E1972: git_worktree_add (worktree.c:388)
==2711==    by 0x551F23: test_worktree_worktree__add_with_explicit_branch (worktree.c:292)
==2711==    by 0x45853E: clar_run_test (clar.c:222)
==2711==    by 0x4587E1: clar_run_suite (clar.c:286)
==2711==    by 0x458B04: clar_parse_args (clar.c:362)
==2711==    by 0x458CAB: clar_test_run (clar.c:428)
==2711==    by 0x45665C: main (main.c:24)

CID:1383993, "In git_refspec__dwim_one: All paths that lead to this null pointer comparison already dereference the pointer earlier (CWE-476)"

As per CID:1378747, we might be called with a NULL repo, which would be deferenced in write_add_refspec

Valgrind log :

==17702== 18 bytes in 1 blocks are indirectly lost in loss record 69 of 1,123
==17702==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==17702==    by 0x5FDBB49: strdup (strdup.c:42)
==17702==    by 0x632B3E: git__strdup (util.h:106)
==17702==    by 0x632D2C: git_reference__alloc_symbolic (refs.c:64)
==17702==    by 0x62E0AF: loose_lookup (refdb_fs.c:408)
==17702==    by 0x62E636: refdb_fs_backend__iterator_next (refdb_fs.c:565)
==17702==    by 0x62CD8E: git_refdb_iterator_next (refdb.c:147)
==17702==    by 0x6347F2: git_reference_next (refs.c:838)
==17702==    by 0x6345CB: git_reference_foreach (refs.c:748)
==17702==    by 0x66BE62: local_download_pack (local.c:579)
==17702==    by 0x5DB48F: git_fetch_download_pack (fetch.c:148)
==17702==    by 0x639028: git_remote_download (remote.c:932)
==17702==    by 0x63919A: git_remote_fetch (remote.c:969)
==17702==    by 0x4ABEDD: test_fetchhead_nonetwork__fetch_into_repo_with_symrefs (nonetwork.c:362)
==17702==    by 0x4125D9: clar_run_test (clar.c:222)
==17702==    by 0x41287C: clar_run_suite (clar.c:286)
==17702==    by 0x412DDE: clar_test_run (clar.c:433)
==17702==    by 0x4105E1: main (main.c:24)

Signed-off-by: Sven Strickroth <email@cs-ware.de>

fixed stack smashing due to wrong size of struct stat on the stack

on 32-bit systems with 64-bit file descriptor offsets enabled
(added -D_FILE_OFFSET_BITS=64 when compiling the test suite)

scripts: add backporting script