* autogen.sh: took away the requirement for automake-1.4,
  changed the messages for getting auto* tools to current
  gnu pages.
* configure.in, configure: added check for Linux Dec alpha
  requiring -ieee flag, fixed test for ipv6
* trionan.c: fixed problem for compiling on Linux Dec alpha
  using native compiler
* doc/Makefile.am: implemented regeneration of win32/libxml2.def.src
  whenever libxml2-api.xml is changed.