changes to project optimisation settings.
reinstated override final to CROB functions.
Changes to compiler settings - optimisation

I am not sure if this is causing any issues.
Added code to Dummy_Handler to work our which IRQ is being called.

Turned out to be the Hard Fault, so I created a Hard_Fault handler in
Main.cpp
Moved DNP3 code to Main.cpp This file is now obsolete.
Various changes to project settings.
Moved in DNP3 code. Added HardFault_Handler
Various changes to project
Various changes to project settings.
Revert "Various changes to project"

This reverts commit 164c754f41a03b7a370937498a2da0ee6fc2ebdd.