stash: update strarray usage

stash: partial stash specific files

`git_strarray_copy` is deprecated (and has been included in
`deprecated.h` for some time). It should not have remained in
the public `strarray.h`. Remove it.

Fix some warnings in main

clone: clean up options on failure

SHA256: more SHA256 support

Support the notion of a home directory separately from global configuration directory

 Define correct off64_t for AIX

#6422: handle dangling symbolic refs gracefully

Fixes issue #6156.

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

Fix build failure with -DEMBED_SSH_PATH

diff_file: Fix crash when freeing a patch representing an empty untracked file

Support OpenSSL 3 in dynamic loading mode

Add new PHP bindings project to language bindings section of README.md

Updates the README.md language binding section to reference a new
project providing PHP bindings at https://github.com/RogerGee/php-git2.

This prevents GIT_MMAP_VALIDATE from failing.
This also prevents git_diff_file_content__unload from attempting to free git_str__initstr.

The git included with xenial is ancient, and lacks sha256 support.

The longest path within a git repository is now a SHA256 format
packfile. Adjust our max length checking to match.

This is much of the plumbing for the object database to support SHA256,
and for objects to be able to parse SHA256 versions of themselves.

Teach the packfile machinery to cope with SHA256.

In clar, an underscore is meaningful; avoid using it incorrectly /
unnecessarily.