Give a better message for access-denied errors

[Adam Winer]

Users can see error messages like java.io.FileNotFoundException: C:\Users\[redacted]List-[redacted].bsxm (Access is denied)

These get dumped in large stack traces, which is extremely confusing.

Ideally, find a good microsoft.com site describing how to fix these and link there for Windows users.

[Adam Winer]

Resolve Issue #642: Update the check for WindowsPermissionException

... at least, I hope this works?

→ <<cset 77ef159afc5a>>