Logging facilities #11
Description
Currently, logging is performed by adding inlined statements, manually formatted, where required. Usually these statements are in an optional block whose execution is controlled by the verbose global variable.
Suggest we create a logging API, so that we can better control what is printed (i.e., more logging levels than currently, which is just on/off). Also so we can control how the output is printed; e.g., as currently, or json-formatted for consumption by posthoc, or something else entirely.
As a first step, I think we need a discussion about whether we use an existing logging library, or roll our own. We also need to think about the overheads introduced by the logger in the situation where output is not desired.