ability to suppress `FILE_LOG` output?

[jGaboardi]

(having no background in c++), how heavy of a lift would it be to implement a non-verbose option for suppressing FILE_LOG output? For an example, here in src/graphalg.Graphalg. While surely not critical, it would be nice to be able to suppress those prints if desired, à la:

Generating contraction hierarchies with 16 threads.
Setting CH node vector of size 3293
Setting CH edge vector of size 8672
Range graph removed 7322 edges of 17344
. 10% . 20% . 30% . 40% . 50% . 60% . 70% . 80% . 90% . 100%

cc @knaaptime

[knaaptime]

funny because I'm actually the one that requested the message be put back into pandana way back when. It's really useful for understanding whether you're properly using multithreading or not. I think given the conda tooling and that we're shipping wheels for all platforms now, it's less of a concern.

I think a better option would be to have a verbose flag or something that would let you suppress most of the time. An even better option might be to have that info stored as an attribute on the network somewhere so you could call it at will. Both of those options would take a reasonable amount of digging though

[jGaboardi]

Any/all this sounds perfect and none of it is time critical, whatsoever. Def a wishlist "when there's time" kind of thing.