Expat 2.0 released

Release 2.0.0 of the Expat XML parser is the end point of the
1.95.X series of releases. The goals we tried to achieve were:

- Solidify and stabilize the implementation of the given API.
- Add desirable features as long as they fit with the API.
- Keep the API backwards compatible, if extensions are needed.

Changes:
    - We no longer use the "check" library for C unit testing; we
      always use the (partial) internal implementation of the API.
    - Report XML_NS setting via XML_GetFeatureList().
    - Fixed headers for use from C++.
    - XML_GetCurrentLineNumber() and  XML_GetCurrentColumnNumber()
      now return unsigned integers.
    - Added XML_LARGE_SIZE switch to enable 64-bit integers for
      byte indexes and line/column numbers.
    - Updated to use libtool 1.5.22 (the most recent).
    - Added support for AmigaOS.
    - Some mostly minor bug fixes. SF issues include: 1006708,
      1021776, 1023646, 1114960, 1156398, 1221160, 1271642.

Karl