Slice 91 - multiple injectors per application

Implemented https://cognifide.atlassian.net/browse/SLICE-91
Rather than creating this `injectorByPath` map, please iterate over all `InjectorConfig`s here, find the one that fulfills this conditions:

    injectorPath.startsWith(config.getInjectorPath());

get the injector name from the matching config and return apropriate injector.