[HPT-118] Add 128x128 view of the page image.

NOTE:  we probably need another way to do this.  This code depends on
the user being able to query Fedora directly, and being able to do
that is probably bad for security.
[HPT-118] Avoid error if Page is unsaved
[HPT-118] Also display image on 'show' page
Merge pull request #14 from mwoodiupui/HPT-118

[HPT-118] Render the page's image in the Page forms