* configure.in: xdr functions may require -lxdr.
* configure.in, src/Makefile.am: Extra linking flags for
building libvirt DLL.
* src/socketcompat.h: Hide Windows Winsock incompatibilities
in a separate header file.
* src/remote_internal.c: Switch to using socketcompat.h /
socket_errno().
* src/test.c: Switch to using socketcompat.h.
* gnulib/lib/arpa/.cvsignore: Ignore another generated file.
* src/qparams.c: Include <config.h>.