Mount failure messages should be more descriptive

[twincitiesguy]

We need to make mount failures easier to track down. For example, if a privileged port is necessary, but the client is not run as root, the error message should indicate this. In cases where the error message cannot spell this out, we need log WARN messages that clearly indicate what operation was unsuccessful and INFO messages to show what operations are being tried.

This is focused on the mount operation for now, but later on, we should apply this same philosophy consistently for every operation.