Revamp user messages

[kmaasrud]

To make things a lot more friendly for users, go over errors and ensure these are propagated properly, with the right context. Make full use of anyhow, as it makes this very simple. This is also a golden opportunity to add some personality to mdzk.

This would be nice to have ready quite quickly, to save us the need of rewriting to much of our codebase in the future.