Make logging more configurable

This PR allows users to configure the path and file name for the application log, as well as whether to create one big log (like L4 currently does), or to use daily logs (like L3 used to do).  And, if you choose to use daily logs, you can specify how many days worth of logs to keep.

Inspired by [this issue](https://github.com/laravel/framework/issues/1585).