MFC r302305: MFV r302260: expat 2.2.0.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update base system libexpat to 2.1.0.

MFC after: 3 days

This commit was generated by cvs2svn to compensate for changes in r178848,
which included commits to RCS files with non-trunk default branches.

This commit was generated by cvs2svn to compensate for changes in r104349,
which included commits to RCS files with non-trunk default branches.