Usernames use everywhere + delays control + smarter follow + comment_hashtag example + bug fixes

• Now you can pass everywhere not only user_id but username too!
• Now you can control delays between likes/follows/unfollows/comments to speed up or slow down your activity
• Now script don't follow users that you yet follow. So now Instabot follows faster.
• New example: comment_hastag.py - just pass it the hashtag and Instabot will like recent medias with this tag
• Bug fixes that you discussed in Issues and Telegram chat.