Use the full organization dict to display orgs

The package page uses only the bits of the organization dict that is returned
from package_show, this doesn't have the image_display_url and therefore
organization images are not shown anymore. This uses a new helper to get the
full organization dict.
Merge branch 'master' into 1592-pkg-org-img
Catch NotFound, ValidationError, and NotAuthorized
Merge branch '1592-pkg-org-img'