Contemplate alternative integrations into backbone-api-client

[twolfson]

Currently, it is a little annoying that we more/less lock in callApiClient functionality before allowing caching mixin. Should we be doing this and is there a better way (e.g. via sync overrides)?

For reference, we are currently structuring it this way to pick up changes from adjustApiClientOptions which could affect parameters and thus the hash for the request. We want the hash to be as sensitive to what is actually sent out/important as possible.