There is now add_replacements which accepts a hash, allowing to
add multiple replacements in one call. This should make mass-adding
replacements look less bulky.
Also including helpers to ActsAsOpEngine to make adding replacements
from a module nicer.
Instead of expecting modules to selectively overwrite
methods of this class, we offer an explicit extension point
where replacements can be registered explicitly.
Thus patching the implementation is not necessary anymore, instead
it can be configured from initializers.
Alexander Brandon Coles