Changes from Chris Jepeway to

Changes from Chris Jepeway to

	in some places use "guint64", on plaforms where it's available,
	rather than floating point (we don't yet use it universally, as
	we'd have to provide code to do 64-bit arithmetic on
	platforms/compilers where 64-bit integral types aren't
	supported);

	use .838096 microseconds rather than 1 microseconds as the time
	stamp units for NetXRay 2.x format, as those capture files seem
	to use that time stamp (that's the Sniffer "PC" time stamp;
	perhaps when Network Associates assimilated Cinco, they changed
	the time stamp units).

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@3027 f5534014-38df-0310-8fa8-9805f1628bb7