Composer support and phpunit testing invoked via Phing

- add composer (http://getcomposer.org/) for dependency management (fix: https://github.com/t0k4rt/phpqrcode/issues/4)
- add phing (http://www.phing.info/) for build management
- setup phpunit for a simple test case
- remove tools for generating concatted version of lib

try it yourself:
- install composer
- run:

    $ composer install
    $ vendor/bin/phing

This should execute the test case.

The README file includes instructions how to set up a test project and use the library.

todos:
- generate temp folder
- generate concatted version of lib
- fix .travis.yaml
- investigate of making use of real namespaces