Extend the ValueOfPointer interface to allow clients to find the raw value of
the pointer (using the getRawValue() method).

Declare the following classes final: ValueStore, ValueByMemoryForScalar,
ValueByMemoryForPointer, ValueByMemoryForRecord, ValueByMemoryForArray,
ValueByRuntimeValueForScalar, ValueByRuntimeValueForPointer.
Update the prototype dot graph generation of SeeC-Clang Mapped process states.
This is getting closer now. In particular we now expand pointers and layout
the pointee Values if those pointees exist in dynamically allocated or known
memory regions, and they are not aliased. We still need to implement the alias
resolution method, and to generate layout for pointers that refer to other
Values (e.g. stack allocated variables).