win32 build fixes, including ingo's suggestions

win32/build_vorbis_dynamic.bat

win32/build_vorbis_dynamic_debug.bat

win32/build_vorbis_static.bat

win32/build_vorbis_static_debug.bat

win32/build_vorbisenc_dynamic.bat

win32/build_vorbisenc_dynamic_debug.bat

win32/build_vorbisenc_static.bat

win32/build_vorbisenc_static_debug.bat

win32/build_vorbisfile_dynamic.bat

win32/build_vorbisfile_dynamic_debug.bat

win32/build_vorbisfile_static.bat

win32/build_vorbisfile_static_debug.bat

win32/vorbis.def

win32/vorbis_dynamic.dsp

win32/vorbis_static.dsp

win32/vorbisenc_dynamic.dsp

win32/vorbisenc_static.dsp

win32/vorbisfile.def

win32/vorbisfile_dynamic.dsp

win32/vorbisfile_static.dsp