
These files are taken from Expat, Release 2.1.1.

The source files have been slightly modified in order to fit them into this
build system. The changes that were made are:

 - Source files now only include config.h (instead of a choice of
   expat_config.h, winconfig.h, etc.).

 - expat_external.h includes harp_expat_mangle.h to name mangle all
   public symbols.

 - Checks for BYTEORDER have been replaced with checks for WORDS_BIGENDIAN.

 - Added '(void)variable;' entries in many functions to eliminate
  'unused parameter' warnings.

 - Added EMPTY_NORMAL_VTABLE macro to eliminate 'missing initializer'
   warnings.

