Support multiroot workspaces with the VS Analysis Engine

[MikhailArkhipov]

How does this analysis engine work with a multi root workspace?
E.g. workspace folder A & B contain two separate versions of Python.
Will we have only one analysis engine or two, will they all use the same version of python?

So far VS project has same interpreter. But not per folder. However, solution can have multiple projects with different interpreters.

[MikhailArkhipov]

VSC can automatically run multiple language servers (one per workspace root). Just need to verify.

[DonJayamanne]

Based on my initial investigation this is most certainly possible within the Extension.
Lazy load instances for the workspaces, instead of loading multiple instances for each workspace folder in a multiroot workspace.

[brettcannon]

This should only lazily load an instance of the language server based on whether a workspace has actually opened a Python file (and set the interpreter).