#5 nfdump-1.6.3p1 fixes

[Peter Haag]

The appended patch fixes some minor bugs and is recommended for all 1.6.3 users:
- Fix potential sequence error in combination with v7 flow data
- Fix timefix bug - make it a compile time option --enable-fixtimebug
If you see flows with durations wy too long, try this
- Zero out unused fields when doing aggregation
- Fix 2 byte sampler ID in v9 tag #48 for IOS-XR

[Peter Haag]

patch-1.6.3p1.txt