Have bflabels and bfdata output key=>value maps

[kspalaiologos]

It'd greatly help in debugging if bflabels and bfdata outputted which adresses correspond to which label names. For example:

@lab
  mov r2, %fun
  mov r1, %target
@target
  jmp %lab
@fun

... and the debugging output:

@lab: 1
@fun: 2
@target: 3

The same goes for bfdata.

[kspalaiologos]

Resolved by 3c0052c