Added concrete implementation classes for assembler and loader.
Altering control flow; to make for easy switching between pipelined mode and standard, a launch() method is responsible for coordinating instruction cycle stages, rather than instructionFetch() automatically calling instructionDecode(), for example.
Written preliminary FetchDecodeStage inner class for pipelined mode.
Written some code for ExecuteStage inner class, and added constructors. Need to coordinate write back stage with execute stage (only required for arithmetic operations).