Add resource instance variables and audit log sample

[goosys]

I have made changes so that instance variables are stored in both the index and create actions, in order to capture controller operation logs and perform other post-processing tasks. Please review.

[pablobm]

I'm ok with this, but I think it should be consistent and always be @resource (and @resources for the plural case).

Thoughts, @nickcharlton?

[nickcharlton]

Ah yeah, I see. Yeah, consistency is important here.

[goosys]

rebased