Option to avoid structure equivalence check

[marcosh]

I suspect that sometimes it would be nice to have the option to skip the check provided by the HalResource::compareResources method.

This is because sometimes resources could have optional fields, or because an embedded resource makes sense only in certain cases

[weierophinney]

This repository has been closed and moved to mezzio/mezzio-hal; a new issue has been opened at mezzio/mezzio-hal#2.