Basic outline of memory, reading lines.

This commit outlines a basic structure for the virtual cpu. Instead of
a compiler and cpu, we're going to start with a cpu that also
functions as an interpreter for the assembly language I'm going to
define.

It will translate assembler into opcodes and load them into memory,
line by line.
Virtual CPU can decode operators and operands.

The state of the cpu is such that it can take lines stdin and
decode the instruction (operator) and the two arguments (operand1 &
operand2). It will emit an opcode, and the integer literal or
dereferenced register operands on stdout.

The current goal is a 12-bit architecture, with instruction, operand
flags, and other flags stored in the first of a 3-tuple of 12-bit
operator, and two 12-bit operands stored in the other two slots.

The next step is to store the decoded program into
memory.