Release Name: 0.2.3

Notes:
* Changed license to Artistic 2.0
* Bug fix for MMap.open with regards to blocks


Changes:
* Changed license to Artistic 2.0.
* The MMap.open method now properly handles a block.
* Some gemspec updates, including the license and description.
* Changed test and example file names.
* Some Rakefile updates, including tasks for running example programs.