only sum to internal if input was processed. added some temp debug pull logging
working feedback test, albeit pullInputs is far from finished
added Add node, needed for testing
cleanup effects test
once again removed bool didProcess optimization, as it makes edge cases cumbersome
when in-place Node that has no inputs doesn't process, zero the buffer. Other cases do not need this.
cleanup and comment pullInputs, although looks like feedback test is still broken
made Node::getInternal protected, minor reorg