Connection Errors are downgraded to warnings

[megatron-me-uk]

RPostgreSQL catches errors and downgrades them to warnings. While this may be useful in some cases, there are many errors which are not recoverable from (e.g. connection errors). It would be preferable to not catch errors and allow the user to decide whether to ignore (current behaviour) or do something else.

A good example of this is in the pool package where a connection is tested at regular intervals and if an error occurs is replaced with a fresh connection. This code is incompatible with RPostgreSQL as errors are downgraded.