updated gitignore for new windows build

[dgonzalezt]

Hi there,

We are including sofacoustics as submodule here: https://github.com/3DTune-In/3dti_AudioToolkit.
It would be useful for us to include a gitignore for intermediate files generated in windows build, plus other minor mods to the windows project file.

Would you rather have us send these suggestions to you here or would you prefer a fork & pull-request?

Many thanks!

[tcarpent]

Hi,
Yes, please send a pull request. I'll have a look as soon as possible.