Would POI actually ship with an implementation (e.g. log4j2) or only with slf4j?
I guess, in the src/bin bundles we need to provide everything you would need to get the library working - if this is only the log4j2-api or slf4j, then we probably don't provide the implementation part. But providing the src/bin bundles is only a leftover from the past, it's the dependency which counts.
... we might upgrade to log4j2, but I'd think we'd want to keep slf4j.
hm, ok ... I'm still undecided - would a log4j2 dependency coming with POI speed up things? On one side our logging is quite basic and slf4j satisfies our needs - on the other side, log4j2 is an Apache project and seems to be quite modern.
