Logic error: Exceptions and handling them

[Nielsbishere]

Function signatures: noexcept should be used if logically, the function can't throw. And throw should be used to indicate a function should.

Handling cleanup: Since a System::log()->fatal can cause an exception, but won't terminate the program, there can be a lot of leaks. This can be fixed by using scoped variables like List or a wrapper class with a destructor.