Log Message:
libgit2: update to 0.28.2.

v0.28.2
-------

This is a bugfix release with the following changes:

* Fix include directory ordering when using bundled dependencies.

* Fix infinite loop when searching for a non-existing repository with
  Windows-style paths including drive prefixes.

* Fix paths with a trailing "/" not always being treated as
  directories when computing ignores.

* Fix false negatives when computing ignores where ignore rules
  that are a prefix to a negative ignore rule exist.

* Fix patches with CRLF line endings not being parsed correctly.

* Fix segfault when parsing patches with file addition (deletion)
  where the added (deleted) file name contains a space.

* Fix assertion failure when trying to write to a non-existent
  locked configuration file.