Added more subreddits from wiki -- all doge-related from http://www.reddit.com/r/dogecoin/wiki/index#wiki_dogecoin_related_sub-reddits
Manually added 'dogetip' to list -- it's not on either page!
[USERSCRIPT] Added check on HTTP requests so list is only updated if requests return OK
Increased robustness of canTip() by forcing parsed subreddit names to lowercase and comparing them to lowercase parsed url