Release Name: 0.9.0

Notes:
* License changed to Artistic 2.0
* Bug fix for OS X and BSD
* Internal reorganization


Changes:
* Changed the license to Artistic 2.0.
* Fixed a bug in the OS X code where a segfault would occur when an attempt
  was made to gather resource usage information on zombie processes. From
  now on that information is always set to nil for zombie processes. Thanks
  go to Tom Lianza for the spot and Philip Kromer for investigating the
  root cause of the failure.
* Removed the FreeBSD code that read out of /proc. It was a pain from a
  maintenance point of view, and most FreeBSD installs do not mount /proc
  by default. The FreeBSD platform now uses the same code that the other
  BSD platforms use.
* Fixed a bug in the BSD code where the ProcTable::Error class had the
  wrong parent class.
* Some major gemspec updates, including an updated license. The platform
  handling logic is now in the Rakefile in the 'gem' task.
* Updated the README file to include an additional acknowledgement, a
  license change and some minor formatting changes.
* The test-unit library was changed from a runtime to a development dependency.