This reverts commit 1714fe93f4.
We actually want this type, it makes things clearer.
Conflicts:
src/tests/eo/function_overrides/function_overrides_inherit2.c
src/tests/eo/function_overrides/function_overrides_simple.c
src/tests/eo/suite/eo_test_class_simple.c
These functions let you pass an array of callbacks instead of just one.
It's more memory efficient to use this if you just add a bulk of events
on the same object.
This commits breaks ABI, and breaks API of the EO_EV_CALLBACK_ADD/DEL
signals (the event info passed).