Search contained in Books Model. Small UI updates in book_list template.
Added get method on BDRObject to retrieve specific BDRObject.  Create Page Object and add the ability for a Book to list its pages.  All to refactor the book_display view.
Refactor book_detail view to use Book object
Return a Http404 exception if the pid provided does not return a BDRObject of some kind
Removed unused Http404 from views.py
Merge pull request #65 from jrhoads/master

Refactor book_detail view to use Book object.  Include alternative titles in book_detail view.