Log Message:
Update to 1.2.25.4. From the changelog:

- Add exception-related files which were new in 1.2.25.3 to MANIFEST
  so they're shipped.  Reported by Tina Müller and Leah Neukirchen.
- Add metadata links to homepage, bugtracker and VCS.  Suggested by
  Gabor Szabo.
- Allow AUTOMATED_TESTING builds against xapian-core 1.4.x.
- Properly handle newer exceptions.  The C++ exception class
  WildcardError wasn't known to the Perl bindings, and would result in
  croak("something terrible happened").  The C++ exception classes
  DatabaseClosedError and DatabaseNotFoundError also weren't known, but
  these would instead be reported as their base classes DatabaseError
  and DatabaseOpeningError respectively.  Reported by Adam Sjøgren.
- README: Update to reflect that the SWIG-generated Perl bindings are
  stable since xapian-bindings 1.4.16.