Created search as a DEFINED function

added search_tweets(term,t_type,count)
This is a defined function that can handle usernames and hashtags without the user having to know the twitter unicode for these.
Instead, it users the t_type parameter to check ofr usernames or hashtags and add %40 or %23 as required. anything else just searches for the term.

Count is to control the Twitter API parameter '&count=...'