Return all threads in a particular subreddit that contain any of the words provided by the user.
python sub_search.py sub=<subreddit name> words=[<list of words>] <search limit>
 python sub_search.py sub=programming words=[python, api, flask, javascript] 25
 1: http://redd.it/2dbzpl (found "python" in title)
 2: http://redd.it/2d8zqf (found "python" in title)
 3: http://redd.it/2ddhir (found "javascript" in title)
with the recent addition of comment parsing the script now takes a very long time to execute. keep this in mind when searching a large subreddit with large comment threads.
- choice to ignore case or not
 - extend search to multiple subreddits
 - search for a string containing multiple words
 - choice to search the submission's title, body, and comments or a combination of the three.