Flag to disable built-in log rotator

I’m setting up logrotate.d for my validator logs (so they don’t take up so much space and I really don’t need more than a day or so left around). However, I noticed that the project is using a Go library to do the log file rotation internally and it’s not configurable.

I’d like to propose a flag to to disable the internal log rotator so the logs will get printed instead to a single log file that node operators can rotate themselves.

Currently when logrotate.d rotates an Incognito log, the server continues printing to the old log file after it’s been renamed. If you delete the current log file, logs stop getting printed completely until the next rotation (when a new file is created). Linux programs handle SIGHUP to force close and reopen the log files to prevent this problem. Logrotate.d will then be configured to call a SIGHUP on the process.

It’s not a huge change, but wanted to see if there were any objections. I’ll try to submit a PR if other people would find this helpful.