nextgen gallery patch: use get_permalink instead of get_page_link when generating gallery links in albums

pull request: https://bitbucket.org/photocrati/nextgen-gallery/pull-request/10

originally commited to my branch https://bitbucket.org/snarfed/nextgen-gallery as changeset b2c4e7a:
https://bitbucket.org/snarfed/nextgen-gallery/commits/b2c4e7ab62cfaba922b98f64faf94feaf39a1b14