Fix filename of simulation record
Init seed by time()
Use append mode for writing simulation record

When running simulation multiple times (if rand-seed is init by time(0))
in same combination of arguments, program will append each record to same file.
Plot multiple flows whcih represent different algorithms on graph
Fix scripts

In python script:
    Add feature which caculating avg time of
    avg peer_complete_time_usage.

    Note: peer_complete_time_usage is caculated from
          multiple simulation records but all apply
          same combination of simulation arguments.

In shell script:
    Fix evaulate string which pass to gnuplot script.