gst/playback/gstplaybin.c: first try autovideosink, then xvimagesink, then error out

gst/playback/gstplaybin.c: first try autovideosink, then xvimagesink, then error out

Original commit message from CVS:
* gst/playback/gstplaybin.c: (gen_video_element):
first try autovideosink, then xvimagesink, then error out
* po/POTFILES.in:
add translatable file
* po/af.po:
* po/az.po:
* po/cs.po:
* po/en_GB.po:
* po/hu.po:
* po/it.po:
* po/nb.po:
* po/nl.po:
* po/or.po:
* po/sq.po:
* po/sr.po:
* po/sv.po:
* po/uk.po:
* po/vi.po:
update translations