wavenc: Go EOS and report an error if larger than 2GB

Submitted by j^

Description

encoding files longer than 1h40m with this pipeline:

gst-launch-0.10 pulsesrc ! queue ! audio/x-raw-int,rate=44100,channels=2 ! wavenc ! filesink location=/tmp/test.wav

creates a corrupt wav files. its opened in totem/audacity but only the first 2GB of data are played.
Ot is possible to open the file in audacity as raw samples, skipping the header(first 20bytes). So data gets written to disk but the wav headers are wrong.