Enable binary editing

at any given point, a user can use the 'replace' command to replace the current pc with a new instruction. There can be multiple instructions, used patching in a jmp to make it work

```
inst1
inst2
inst3
```

-control 'replace inst2 with instA;instB;instC'

```
inst1
jmp tmpsection0
inst3

tmpsection0:
instA
instB
instC
jmp back
```