From Richard van der Hoff:

From Richard van der Hoff:

Among the improvements are:
- fixes to call-tracking (it's now less likely to confuse two separate
calls, for instance)
- improvements to Information Element dissection (clearer dissection,
dissects more IE types, easier to extend)
- you can now filter on the content of DTMF packets
- Analysis of timestamps (calculation of absolute timestamp, and packet
lateness).
- fixed a couple of assertion failures in subtle corner-cases.

negative relative times:
   - get_timedelta()
   - addtime()
   - ftype-time.c:relative_val_from_unparsed()

I've also moved get_timedelta() and addtime() out of calldata.c into a
new file, epan/nstime.c, as I needed to use them in a dissector I'm
working on (and they therefore needed to go into libethereal).

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@15201 f5534014-38df-0310-8fa8-9805f1628bb7