Added PHPUnit dependency and simple tests.

Added PHPUnit bootstrap to setup class autoloaders.
The MyRequestTest currently tests for correctness of required HTTP request
headers.
Added Travic CI build file.
Update phpunit.xml.dist
Added Travis build status image.
Skipped phpunit install.
Rename autoloader.php to AutoLoader.php
Fixed composer build invocation.
Empty User-Agent header no longer accepted.
Updated unit tests. Consts now in XML config.
Added basic MyResponse unit tests.
Fixed PHP 5.3 build.
Changed Tests sources formatting.
Converted tabs to spaces in all sources.
Updated license info in composer.json
Return empty list instead of error 404.

API calls to /additives /additives/search and /categories will now return empty [] list of no items are available instead of error 404.
Fixed Issue #11. No auth for / route.