Sideboard should complain at startup if there isn't a valid/complete logging setup

[thaeli]

If there are no log handlers defined, Sideboard will silently just not log anything. This should be a warning at startup if the logging config appears to not result in things being logged. Perhaps even add a printout on startup of what the logging config it's read in is.

I'm not convinced this should be a fatal error, but it should be noted on startup to stdout/stderr at least.

[RobRuana]

So, a straight print() statement? Like:

print('WARNING: No log handlers configured')

I am in favor of this. I'd even be in favor of having a console logger defined by default.