Router: Update and Clarify the Inline Documentation for VMCommSystem

After testing on my local I2P testing network, I've found it desirable to narrow the scope of this pull request.

This MR just clarifies the documentation for VMCommSystem, so that people reviewing the code base in the future will have an easier time understanding the purpose of VMCommSystem.

It's counter-productive to have a blanket setting that disables NTP and Reseeding in the context of a testing network. First, there are already configuration settings that can be used to disable these if desired. With respect to NTP in particular, routers in the testing network begin to pick up a clock skew if they don't have access to a NTP server.

So, I've cut all that out since my previous MR, and just clarified the documentation.