Remarks for FileSystemWatcher is wrong and/or incomplete

`FileSystemWatcher` has a quirk in that it does not work for all types of remote watching, see https://github.com/dotnet/runtime/issues/16924#issuecomment-207118907.

Given that this is true (which I think it is based on FileSystemWatcher not working for me), the documentation is not very clear about this. It mentions in its initial `remarks` that `You can create a component to watch files on a local computer, a network drive, or a remote computer.` and does not mention any limitations to this other than, under Events and Buffer Sizes that `Remote computers must have one of the required platforms installed for the component to function properly.`.

I take this to mean that the remote computer must have a .NET version installed, rather than being a specific type of share.

I think that this behavior warrants its own remark under `Please note the following when using the class.`