Move to use the ZipContainer library underneath.

All the same functionality in a re-usable package.
Bump to use version 0.9.0 of zip-container.

The exceptions are now more generic so look more relevant.
Update and polish the example scripts.

All scripts are now executable and also provide better usage information.
Update the Rakefile and gemspec.

Better summary included and some files have changed names.
Merge branch 'next'

* next:
  Update the Rakefile and gemspec.
  Update and polish the example scripts.
  Bump to use version 0.9.0 of zip-container.
  Move to use the ZipContainer library underneath.
Update ReadMe and Changes for release.