automate Windows development environment setup

[rakslice]

It would be nice to have automated set up build environments suitable for development on, for reasons:

• to make it viable for devs with no Windows experience to at least try their B2/SS code changes on Windows
• to get around inconsistency in the resulting environment
• to save actual set up time

Devops tools for this such as Vagrant are available. Vagrant supports Windows guests, so in theory this could be done for Windows; I have no experience with Windows guests in Vagrant.

Licensing requirements and avoiding sketchy unverified prebuilt system images are a concern; maybe look at the stuff Microsoft provides for web testing: https://app.vagrantup.com/Microsoft/ as a starting point

[rakslice]

• This isn't a substitute for CI-focused hosted build environments such as Travis CI or Appveyor.
• This isn't completely a substitute for old fashioned development environment setup scripts or just documentation, as there will always be people who are prepared to do a bit of development to fix a bug but don't have the network capacity or the machine resources to pull down and run a whole separate VM image to do so or even go much beyond whatever development tools they already have installed.

[rakslice]

But generally, Vagrant runs on all sorts of platforms; my hope is that if there's a super convenient way to prepare a Windows development environment it's more likely that people hacking on this on other platforms actually do the corresponding stuff on the Windows side for their changes and not have the macemu project once again get into the state where the Windows part of the codebase is broken and unbuildable for years