Added gitattributes and added alot of Windows specific stuff to gitignore.

The gitattributes is just the auto generated one. It should help when
changing Visual Studio Project files.

I got gitignore from [1] and [2] and remove some extraneous stuff that
we don't need. Tell me if it causes problems and I'll try to fix it.

[1]
https://github.com/github/gitignore/blob/master/VisualStudio.gitignore
[2] https://github.com/github/gitignore/blob/master/C%2B%2B.gitignore