changed a lot of .read calls to use get_readable_fileobj
translated UKIDSS reading from progressbar to get_readable_fileobj as per Issue #23

Conflicts:

	astroquery/ukidss/ukidss.py

minor bugfix in IRSA fileobj useage

added astropy.utils.data import (oops!)
added cache=True to some functions (not all, becuase there should be no
need to cached index pages / it could lead to problems)