videoconvert: Update disted orc files
videotestsrc: do not set TIME duration when asked for another format

This fixes asserts in pipelines such as:

gst-launch-1.0 videotestsrc num-buffers=1000 ! x264enc ! h264parse ! \
   matroskamux name=mux ! filesink location=test.mkv
textoverlay: don't leak GAP events
tools: gst-play: add dot file dumping for pipeline graph debugging