GLOG / cout compatibility

[thclark]

We use the google logger (glog), where source code contains printout of informational items and progress:

std::cout << some_useful_stuff << std::endl; \\ is equivalent to
LOG(INFO) << some_useful_stuff; \\ except this goes into the log file rather than the console

I don't want to change all the std::cout statements throughout the codebase (as I'm using some subrepos from third parties etc, and I want the code to remain as standard as possible). So I'd like to keep writing std::cout for informational level logging, but have that pushed to log statements.

This SO post summarises my need, with some tentative solutions.

Current workaround: use simple COUT statements so we can see progress as we're running and developing, then move to LOG macros when we're ready to deploy.