Add support for logging output using Logback

This version includes support for building through both Ant and Maven.  Functionality added:

- Support for outputting metrics using Logback with time and size based roll over but without the file being renamed. We had difficulties on Windows with the DailyKeyOutWriter and file renames.
- Tidied up the code for KeyOutWriter and DailyKeyOutWriter to remove repeated code and shorten the methods.
- Added the ability to set the delimiter from a setting as opposed to it being hardcoded to "\t". Note it still defaults to "\t".