ironic-lib is being retired; this change imports any used code from
ironic-lib and updates references.
This contains some changes to how we throw exceptions; aligning
ironic-lib code with IPA practice to have all exceptions be a RESTError.
This also allows us to remove code around serializing ironic-lib
exceptions.
Change-Id: I137340ce6820c68d8e0f1a32668151bba7b1ddd7
8b18184e2d