create a wishlist

[mgafner]

wishlist: put a file in $fadecuthome with a list of artist/titles
start fadecut with special option (-w for example) and fadecut
will rip/process only files which are on the wishlist.
this should work with many fadecut processes in parallel, to scan on
many internet-radio stations in parallel to complete the wishlist as
fast as possible

(Issue taken from TODO.md)