Fixes to branch predictor processing scripts.

Created by: rosethompson

• Addeed script to sweep sim_bp for btb.
• Fixed issue 250. instruction classification was not correct for jalr ra (non zero).
• Added support for branch counters when there is no branch predictor.
• Updated bpred-sim.py to take command line options to select between sweeping direction, target, class, or ras prediction.