a composer plugin to offer a clean and unproblematic way to install magento modules

currently only replaces the "magento-hackathon/magento-composer-installer" as a composer-plugin.
In the long run it will provide an more easy and extendable way to deploy magento modules into the correct structure and gives more control when and for which modules this happens.

Also it will provide some additions, making use of composer libraries and composer in general usable with magento as a whole.