Implemented PSR-4 support and added trait test coverage.

This flattens the directory structure down, drops PSR-0 support for PSR-4 and adds an example test case that utilizes the trait. A php 5.3 specific phpunit configuration was added to omit testing the trait for 5.3 environments. Travis was updated to run this new 5.3 configuration in that environment to prevent 5.4 syntax errors.