Multi-domain setup

[mpolishchuck]

So OJS version 3.3.
It still cannot automatically handle multidomin setup. The base_url config variable only controls link generation process. But it does not have a leverage how OJS detects current context.

In fact it is expected behaviour. The OJS platform does not implement full routing cycle which means it cannot serve all generated URLs by itself. The missing features should be implemented in web-server configs.

This time instead of modifying OJS code (#4) it is better to provide proper web-server configs. The best chioce is Apache with mod_php7. Only in this case the PATH_INFO variable is set correctly. The FastGCI environments have the issues with setting PATH_INFO. That's why popular frameworks like Yii or Symfony use some workarounds to determine path info. The last time we've used some workarounds in OJS but it caused the web-cache problem (#12).