Adding new options to record population steps

[cnstoll]

Some speculative work on adding a few new customization options to the record population workflow for supporting:

• Injecting a primary key where the API does not include one, but you have access to it externally
• Custom population steps where injecting new data into the flow is required, such as if the API doesn't include certain data that you have external access to

Feedback is very welcome

[larsacus]

Are there any restrictions on what this primary keyed object should be? I'm betting it should at least be NSCopying compliant, no?

[cnstoll]

Yeah thats definitely true. Do you think thats worth adding? That would also make it more clear that this is NOT for use with record to parent record primary keys, since NSManagedObjects don't support NSCopying.

[larsacus]

I always prefer compile-time errors and warnings over exceptions and assertions.

[cnstoll]

Merged into the 1.3.0 branch.