Original commit message from CVS:
* ext/soundtouch/gstpitch.cc:
* ext/soundtouch/gstpitch.hh:
Implement LATENCY query and notify about latency changes.
Unfortunately we don't have a fixed latency but it changes
a bit with each buffer so we only send an LATENCY event with
the maximum latency if it changes.
Always calculate the timestamp, duration, etc from the sample
rate instead of using a pre-calculated duration for one sample
to prevent large rounding errors.
