gitignore: ignore Visual Studio files
gitignore: ignore Visual Studio files

PR-URL: https://github.com/libuv/libuv/pull/59
Reviewed-By: Bert Belder <9f2ff180696da386c1be31b4507155616db25dc6@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <8a7991f6950ea189abf159d6ec98d2fcc13dc5f6@gmail.com>

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso