Chip-8 Decode

[ejrbuss]

The Chip-8 emulator needs to decode instructions and call the appropriate operation function. This can be done using a variety of techniques (switch case, lookup table, etc.) The function void decode(Chip8VM_t * vm, word_t opcode) declared in includes/chip8.h and defined in src/chip8.c should perform this task.

[john-curry]

Implemented a decode method and an evaluation method. Decode decides what instruction is being called and and evaluate gets the registers and values from the instruction. It then calls the appropriate method in ops.c