Related to #83, this is an improvement for the various settings that Rend uses.

In the latest batching handler code, there's a bunch of settings that will be passed through by command line arguments. This quickly gets messy. A config file would be easier to manage and commit with the code.

The upside of a static config file is that Rend can be packaged with an external one to adjust settings as needed. The file would be trackable through version control, unlike our current situation where it is set by dynamic properties that the startup script reads and applies. It also allows

The downside would be less readable code in that the values of the properties are not necessarily known during development.

The file format can be very simple and allow only specific data types, e.g. an int or a float. The code reading would need to know whether the number is meant to be an int or float and ask accordingly of the metrics package.

In conjunction with #83, this data will be overridable by dynamic settings changed by the user as well as command line arguments.

The order of precedence goes:

1: Dynamically set configuration during runtime
2: Command line arguments
3: Config file contents