Update Windows setup script

[calebcartwright]

The Windows dev_setup script will currently do a force install of the VS vctools in order to support Rust's default MSVC target on Windows, if Rustc is not available.

The vctools install may not always be necessary, so if the script detects Rust has not been installed, it should check the minimum VS2013+ vctools install before attempting to install it.

The vs tools install almost always require a system restart, which means that in the event that the script does need to install the vctools, it cannot continue to the next steps prior to the user restarting.

This setup should be split out into a separate script/sequence to improve the dev experience

[calebcartwright]

https://devblogs.microsoft.com/cppblog/finding-the-visual-c-compiler-tools-in-visual-studio-2017/