[HPT-160] Missed some references to physical_page
Merge pull request #32 from mwoodiupui/HPT-160

[HPT-160] Missed some references to physical_page
[HPT-153] Start testing for linkage rules
Add siblings validation and fix the test to detect it properly
Script to purge all non-system objects from a Fedora
Flesh out test for required siblings
Add insertion test.

I thought we could use validation support much more than turned out to
be possible.  What I learned:  validation can't refer to other
ActiveFedora objects or things get tangled.

I also had to install a bypass switch in #save so that it can
recursively #save the siblings when they must be modified.  There's no
way for the tests that I moved from validation to work for both 'save's.
add delete test
Clean up tests, make link presence checks more rugged