fixes #3931: rbvmomi gem has been pinned to ~> 1.6.0
fixes #4161: plugin ActiveRecord models that do no define 'name' method no longer throw NoMethodError when to_s is called
Fixes #4032 - Use object.id for comparisons
fixes #3697, #3701 - more comprehensive field validations
refs #3697, #3701 - fix test with multiple validation failures