Resolve #1 "Port Interface", #8 "Port Coupling"

Adds:

• Port interface functions for InputPort and OutputPort.
• Functionality for connecting ports and signals, both via signals and ports.
• Tests that verifies that the functionality has been correctly implemented.
• Fixes to older code so that it works with the new interfaces.
• Minor functionality for connecting operations in their constructors.

Closes #1 (closed) and closes #8 (closed)

b_asic/abstract_graph_component.py

@@ -5,6 +5,7 @@ TODO: More info.
 
 from b_asic.graph_component import GraphComponent, Name
 
+
 class AbstractGraphComponent(GraphComponent):
     """Abstract Graph Component class which is a component of a signal flow graph.