Add VC6 projects for the test executables.

win32/vc6/example_deconstructor.dsp

win32/vc6/example_deconstructor_alt.dsp

win32/vc6/example_reformatter.dsp

win32/vc6/example_reformatter_alt.dsp

win32/vc6/libyaml.dsw

win32/vc6/run_dumper.dsp

win32/vc6/run_emitter.dsp

win32/vc6/run_loader.dsp

win32/vc6/run_parser.dsp

win32/vc6/run_scanner.dsp

win32/vc6/test_reader.dsp

win32/vc6/test_version.dsp

win32/vc6/yaml.dsp

win32/vc6/yaml/yaml.dsp

win32/vc6/yamldll.dsp

win32/vc6/yamldll/yamldll.dsp