[Rd] Feature request: Change default library path on Windows

[Steve Haroz]

> That said I dont have a super strong opinion
Neither do I. As long as it's somewhere other than USER/Documents

> Another option would be to allow users to set the default library location from within the windows installer (if you can't already).
Currently, there is no option during install, but that is a separate issue.
I'm more concerned with the default location rather than how to change
it. Users won't know that the current default (User/Documents) is
incompatible with their cloud service until after they've installed R
and tried adding libraries.

-Steve