Google "I'm Feeling Lucky" Image

This script prints the result of the very first image in a Google Image
search for the given query.

GET Parameters: 
 - q: the query (string, required)
 - cache: show the cropped cached image instead of the original image (boolean int, defaults to 1)
 - p: which image to start at (positive int, defaults to 0)
 - redirect: redirect to the image rather than display its contents (boolean int, defaults to 1)

Examples:
- google-image.php?q=escalope            # => redirect to the cached image
- google-image.php?cache=0&q=escalope    # => redirect to the original image
- google-image.php?q=escalope&p=1        # => redirect to the cached second image
- google-image.php?redirect=0&q=escalope # => print out the cached image