Add XDR support (only built #if cygwin, for now)

[Dave Korn]

On 02/03/2010 13:56, Charles Wilson wrote:

> Finally, when rebuilding, I found a thinko in xdr/Makefile.am:
> "EXTRA_SOURCES" is a bad name -- automake gives the following warnings:
> xdr/Makefile.am:20: variable `EXTRA_SOURCES' is defined but no program or
> xdr/Makefile.am:20: library has `EXTRA' as canonical name (possible typo)
> 
> why this is a problem, but GENERAL_SOURCES and ELIX_SOURCES are not, I
> don't know, but the attached fixes both that and regenerates xdr/Makefile.in

  Because EXTRA_*_SOURCES has special magic meaning to libtool (well, to
automake's interface for driving libtool generation to be precise, but ykwim).

    cheers,
      DaveK