Implemented a lot of jump calls, flags, missing opcodes, and opcode overloading

- Overloaded many opcodes
- Implemented most (useful) flags and made sure all opcodes which affect flags actually affect them
- Implemented a lot of the conditional jumps as a result of the flag work
- Added a few missing operands which have yet to be defined
- Changed how DecodeOperand works, it no longer returns a pointer but rather changes the vm_t pointer