Done with liveness.

I think I finished my liveness analysis. Well, at least for virtual registers. You can check my API here. The implementation is here. Most of my problems were due to forgetting the '&' when trying to obtain references to vectors in the matrix... living and learning... Also, the matrix tends to be quite sparse, for basic blocks only have two branches at most. I may try to optimize it later. Tomorrow I will improve the control flow visualizer with the liveness analysis information. Also, I have to incorporate physical registers in the analysis, but I think such registers are not alive outside basic blocks. Wanna see the result of today's toils? Check it here. It is quite beautiful to me. Tomorrow: "que venha o visualizador"...