added --seq arg, to choose sequential refnums over random (default)
generate 32-bit limited values for 64-bit random refnums
fixes a type in symbol name
symbols are taken from an external file
allow delimiters [:-.] in MAC addresses
improve symbols file reading (clean up lines, reject unsupported)
print params header even if not verbose mode and improve it
created nasdaq_traded_max4.csv - list of stocks traded on NASDAQ, name limited by 4 chars
generate additional timestamp event msgs if orders/updates overshoot initially planned run time
pad stock symbol names in order msgs with zeros