More style fixes.
Remove unused tcpmss, tcpws, and tcpts from NpingOps.
Add NpingOps::echo_payload_set.
Kill extra whitespace in NpingOps.h.
Move declaration of NpingOps::getTotalProbes.
Comments on NpingOps fields.
Consolidate NpingOps public data members.
Normalize public/private indentation.
Move private data members to the top of NpingOps.h.
Increase packet count from 32 to 48.
Use hex constant for packet count.