Fix tag parsing so it doesn't die when it ends with a letter that's a
rating.
If you search for the single tag "poops" it will search for "poop" on
rating s. If you really want to search "poops" then you will have to
provide the rating explicitly. Even if it's the default rating you want.
Now chooses a random image from the results.
Merge pull request #3 from Ijwu/master

Fix tag parsing so it doesn't die when it ends with a letter that's a rating.