Fetch directly from Microsoft rather than using installed version of MSVC

[nowster]

Checklist

• Used a fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

Fixes #20
Closes #18

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• It looks like the 'vs2019_linux-64' output doesn't have any tests.
• It looks like the 'vc' output doesn't have any tests.

[nowster]

Note that existing recipe does not package the license file, which is proprietary and most definitely not BSD as claimed.

[beckermr]

bump here @conda-forge/core

[beckermr]

bump @conda-forge/vc

[nowster]

There's currently a problem building this due to run_exports pinning conflicts with previous installed versions of this package. I haven't been able to resolve them using the ignore_run_exports mechanisms.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• It looks like the 'vs2019_linux-64' output doesn't have any tests.
• It looks like the 'vc' output doesn't have any tests.
• Jinja2 variable references are suggested to take a {{<one space><variable name><one space>}} form. See lines [37, 37, 40, 40].

[isuruf]

This looks good to me. Can we do VS2017 first though (or both VS2017 and VS2019)?

[traversaro]

Hi everyone, I am not sure if anyone is working on this, but I would be happy to give an hand to get this merged. If the blocking issue is still:

Can we do VS2017 first though (or both VS2017 and VS2019)?

I can work on this.

[isuruf]

Yes, it's the only issue right now. Thanks for taking a look

[traversaro]

I started looking into this, I have a few question before actually opening a PR:

• For supporting both VS2017 and VS2019, does it make sense to use two separate branches as done in normal "feedstock" to generate different packages, or you had in mind another strategy?
• There is any reason why 32-bit is still supported in this PR, or we can just drop support for it?

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• It looks like the 'vs_linux-64' output doesn't have any tests.
• It looks like the 'vc' output doesn't have any tests.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• It looks like the 'vc' output doesn't have any tests.
• It looks like the 'vs_linux-64' output doesn't have any tests.

[isuruf]

Thanks @nowster