Make stats counters (Rxbytes, Txbytes..etc) 64bit so larger values can be supported

[GoogleCodeExporter]

This is an enhancement request.

The current stats counters (RX bytes, TX bytes ..etc) are using 32 bit 
variables.

Since Ostinato supports 10G adapters (and can crank out very high data rates), 
these counters can easily be over run and no reflex the actual values.

For systems that support 64bit (Like most all the Linux implementations) - 
please make these counters 64bit.

Current code used is Ostinato 0.5 on an OpenSuse 11.4 X86 64bit machine.

Original issue reported on code.google.com by [email protected] on 2 Apr 2012 at 6:26