Custom version of an addon shell to call architecture specific retroarch and cores

Assets provided under te resorces/assets folder are being shared here under Creative Commons 4.0 By Attribution (https://creativecommons.org/licenses/by/4.0/). Credits go back to Lakka project for those.

Addon inspired on version from kszaq (https://github.com/kszaq/openelec.retroarch-aml) and also used feedback provided by other users such as sammaz. Many thnaks to them and folks from Lakka project!