began new infrastructure

Yep, this is another one of my "famous" sweeping rewrites. Expect things to break.

Goals for this are:
- Greatly simplify node connections (particularly with arrays) so the code requires less maintenance/is more stable
- Redesign node structure to address issues where UI would stall for lengthy periods of time
- Less reliance on shared ptrs/greater reliance on QObject system for inheritance/memory management
- General code cleanup and improvements

app/widget/timelinewidget/tool/transition.cpp

@@ -147,12 +147,14 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
         Block* in_block = (ghost_->GetMode() == Timeline::kTrimIn) ? active_block : friend_block;
 
         // Connect block to transition
-        new NodeEdgeAddCommand(out_block->output(),
+        new NodeEdgeAddCommand(out_block,
                                transition->out_block_input(),
+                               -1,
                                command);
 
-        new NodeEdgeAddCommand(in_block->output(),
+        new NodeEdgeAddCommand(in_block,
                                transition->in_block_input(),
+                               -1,
                                command);
       } else {
         Block* block_to_transition = Node::ValueToPtr<Block>(ghost_->GetData(TimelineViewGhostItem::kAttachedBlock));
@@ -167,8 +169,9 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
         }
 
         // Connect block to transition
-        new NodeEdgeAddCommand(block_to_transition->output(),
+        new NodeEdgeAddCommand(block_to_transition,
                                transition_input_to_connect,
+                               -1,
                                command);
       }