MFC r340127,340133,355085: libbsdxml (expat) 2.2.9.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

MFV r302260: expat 2.2.0

Approved by: re (kib)

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.

Virgin import (trimmed) of eXpat v2.0.1. Discussed and tested with
sam and phk who are the two consumers of this library. If there is
any other fallout, email me and I will take care of it.

Approved by: sam, phk

Virgin import (trimmed) of eXpat version 1.95.5