Composer handles ZF dependency and autoloading

Composer support has been added. Using 'composer update' downloads
the Zend Framework 1 dependency, from Packagist (can be changed in
the 'composer.json' file). There is no need to use git submodules.

Composer also handles autoloading the classes. Even though ZF1
uses 'require_once' statements, using Composer to do all autoload
is working.
Tiny documentation fix in Oara_Factory

The documentation did not correspond to the actual behavior,
which confused IDEs (and the developers as well). It's fixed.
Merge pull request #6 from pavelsmolka/master

Thank you for the merge, I am going to test it and it will be part of the project. Cheers