hook: for python hooks, also return whether an exception was raised The hook code treats python hooks raising an exception and returning True as the exact same. This is OK for hooks themselves, but other code that wants to invoke external code using the same underlying code is a bit more interested in making a distinction.

hook.runhooks: return a dict of result values This will be useful to other calling code that would be interested in what the individual hooks return.

hook: factor out determination of hooks from running them This will allow other code to run a predetermined series of hooks.