accepts_nested_attributes_for: pass :reject_if => :all_blank or :reject_if =>:any_blank

[Hardbap]

https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/2501-any_blank-and-all_blank-options-for-accepts_nested_attributes_for-reject_if

Instead of having to keep writing the same :reject_if procs over again it would be cool if accepts_nested_attributes_for would handle a couple common scenarios.

Thanks Mike