scraper logic - Githubissues

Sketch of the scraper logic. I'll code it soon.

user choose system (subdirs of $HOME/RetroPie/roms/).
find every file in each dir with the valid extensions (obtained from es_systems.cfg).
xargs the files to hascheevos.sh.
get ROMs that have cheevos from stdout of hascheevos.sh.
update <achievements> field in the respective game entry in gamelist.xml.

meleu / hascheevos