Fix query for phrases and add --best and --bestof options

Basically with this you can:

* Search with more words
`gh gif 3 -R "Jim Carrey Dancing"`

* Choose to use the best result (The index 0)
`gh gif 3 -R "Jim Carrey Dancing" --best`

* And specify how much items consider in the random
`gh gif 3 -R "Jim Carrey Dancing" --bestof 3` (Will use one of the first three results)

I have no idea if `--bestof` is a good name, because we are not choosing the best of the first N items, its random... but I could not think in any other better name.`