Improve error handling

[ghost]

At the moment is a boolean value is returned from each call to a SMCWrapper function.

Upon failure however, a simple false value doesn't provide any insight as to the reasoning behind the failure. There are often multiple potential points of failure behind an error.

Resolution;

• Implement some form of State (simple primitive int?) in SMCWrapper
• Either document state values or simply define a load of macros against them. (Potentially not, due to the sheer number involved in SMC.h)