LBANN LOG

[samadejacobs]

Need a general (and nice) structure to handle logs in LBANN. We could take a cue from Caffe (Caffe uses Google logs (GLOG)).

[davidHysom]

googling: google GLOG parallel
turned up a lot of results, but none that indicated GLOG works with HPC/parallelization. I'm in favor of rolling our own, for these reasons.
first, using GLOG means we need to grok yet another external API.
second, I'm guessing GLOG has lots of bells and whistles that we don't need. But since they're there, someone will use them, confusing the rest of us
third, it's pretty easy to write a logging class using a singleton. I'll be happy to make this happen.