PoE Response Number Issue and Performance Mode is disabled by default

[DakaiKang]

(1) In the PoE implementation of PoE. It uses the same response/performance manager as PBFT. However, PBFT requires f+1 responses while PoE requires 2f+1. We need to fix this issue by adjusting the related functions in PoE. (2) In the scripts for running the PoE performance experiments under 'scripts/deploy/performance' and 'scripts/deploy/performance_local', the performance mode is disabled by default. I would suggest adding 'export performance=true' to the scripts.