Use curl for url-escaping
Use curl for url-escaping

Currently, our url-escaping/unescaping routine only encodes/decodes the
two characters "?" and "&" by their urlencoded entities and vice versa.
LibCurl, on the other hand, handles all the other problematic entities,
e.g. " ", and related edgecases.

newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat,newsboat/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat