Ability to clear errors?

[vaudevillen]

Because eachError is backed by a ConflatedBroadcastChannel, it'll replay errors, but I might not be concerned with any previous error values. It would be nice if we could either clear the error, or have this work like a flow and "drop" the first error. Also, this seems related to issue #13, and could be solved by adding the ability to manually update the error value

[asarazan]

From a philosophical standpoint, a system should be considered "in error" for the entire time that it cannot acquire a new value. Therefore the only "true" way to clear an error is to execute a successful fetch.

Right now I'm leaning toward restricting any external control over errors because it might confuse or dilute their meaning.