Added generic solution example to deal with derived types

Marshaller can now potentially dispatch derived types that formerly could not have been distinguished.
A solution for the type Magazine was implemented following this pattern:
a) Checking for DerivedTypeAttribute at certain points in the code where our derived types would pass through
b) Making sure our incoming ListBlock adheres to the expected structure for the derived type we want to dispatch
c) Searching for the type referenced by SQF in our assembly
d) Unpacking and dispatching the ListBlock elements we are interested in while passing the in c) inferred type along

- GenericWeapon deleted
- Obsolete test strings in MarshalTest/Program deleted