Only share files visible in the "solution view" when sharing from VS

[Chuxel]

Currently when a solution is shared in VS, the folder structure under the solution is also shared. It is essentially what you would see if you clicked the "Solutions and Folders" button and switched to "Folder view" in VS.

(Note: See #31 on supporting "solution view" for the guest and #46 on supporting projects outside of the solution root for these problems.)

Solution View:

Folder View, what Guest Sees:

In most cases this is fine as it provides the "guest" with a full picture of the project structure. However, what is shared can be a bit unexpected given the "host" shared from a view that may have hid a number of files or folders. For example, "test12354.txt" above was not in the visible in "solution view" and thus the host may not have realized it was shared.

In addition to allowing users to specify certain files or folders as "host only" (#52) and thus not visible to guests we could automatically only share files visible in the solution explorer when the host shares while "solution view" rather than what is visible in folder view to keep things consistent.

[lostintangent]

This has been resolved as part of the fact that "Solution view" is now supported in Visual Studio.