DRY up Log4Net Appender config

Related to #63

Our Log4Net config has gotten pretty repetative, with the same settings defined for multiple `RollingFileAppender` config.

This PR is about finding a way to DRY up our Log4Net RollingFileAppender config, so we only need to specify the differences (ie, the log file location) from the defaults (ie, the rolling settings)
> btw, ability to switch off EDB logs requires some extra functionality

I don't think we should be manually "adding" appenders like this.  Rather, just let our custom appenders be added in the config; that way "switching them off" is as simple of commenting  out / deleting the config