Numerous changes were made to git functions to use an object_id
structure rather than sending sha1 hashes as raw unsigned character
arrays.  The functions that affect cgit are: parse_object,
lookup_commit_reference, lookup_tag, lookup_tree, parse_tree_indirect,
diff_root_tree_sha1, diff_tree_sha1, and format_display_notes.

Commit b2141fc (config: don't include config.h by default) made it
necessary to that config.h be explicitly included when needed.

Commit 07a3d41 (grep: remove regflags from the public grep_opt API)
removed one way of specifying the ignore-case grep option.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>

Update to git version v2.13.4: With commit 8aee769f (pathspec: copy and free
owned memory) the definition of struct pathspec_item has changed with the
expectation that pathspecs will be managed dynamically. We work around this
a bit by setting up a static structure, but let's allocate the match string
to avoid needing to cast away const.

Updated a patch from John Keeping <john@keeping.me.uk> for git v2.12.1.

Update to git version v2.11.0. Function write_archive()
dropped argument (int setup_prefix).

Update to git version v2.10.2, no changes required.

Update to git version v2.10.1, no changes required.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Upstream continues to replace unsigned char *sha1 with struct
object_id old_oid. This makes the required changes.

The git lib has its own main function now. Rename our main function
to cmd_main, it is called from main then.

Update to git version v2.9.1, no changes required.

Signed-off-by: Christian Hesse <mail@eworm.de>

Update to git version v2.9.0, no changes required.

Signed-off-by: Christian Hesse <mail@eworm.de>