Please display an identifying string (version and/or commit and/or build) on stdout at Firefly server startup time.

This is meant to be helpful to the LSST data center configuration staff, for instance so that they can confirm that the expected versions of components are running in a particular LSP instance.

This story should be prioritized according to how much work it is. If it's a quick fix, please do it soon, as it will help during the rapid turnover of Firefly versions that is likely in the next couple of months. If it's a significant amount of work for some reason, it may not be worth trading against other required features.