#447 Add extra timestamps to gstreamer plugin's messages

[Ted Mielczarek]

Attached is a patch that adds "start_time" and "end_time" fields to the messages that the gstreamer plugin produces. I wanted to generate captions from a source video, and the gstreamer plugin makes it easy to process various media formats, but I needed the timing information.

You can also try this patch from my GitHub branch:
https://github.com/luser/pocketsphinx/tree/gst-extra-timestamps