Create logical vmethod for pad events and queries
Merge remote-tracking branch 'MathieuDuponchelle/aggregator' into aggregator

Conflicts:
	libs/gst/base/gstbaseaggregator.c
Start making the pad event logic per pad
Make the tests pass again after per pad condvaring
Revert "Make the tests pass again after per pad condvaring"

This reverts commit d2727fcb6255f0b5db131927418ccf484823ec58.
Revert "Start making the pad event logic per pad"

This reverts commit 32c8ac3efed0e3dd04c2510997eb5a8b85f16543.