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)
Edited by Angus Lothian