Generates a json file with flows that satisfy the command line filter.
parsing command line:
$ python filter_tool.py -ifolder ../Data/ -BE 5.0 -dp 53 -o stdout
enchanced command line functionality: -ifilter "dp = 53 and be > 5.0"
Prints out a summary for all flows: number of flows, max/ave/standard deviation of a message length, etc.
$ python summary_tool.py