Simple bar with foreground color on the background color

use gst_check_drop_buffers in videotestsrc to
clear the global buffers list.

Use UYVY for unit tests, it's exactly the same as Y422.
(which is currently disabled in videotestsrc)

Fixes #629672

This reverts commit 129af0d8.

This shouldn't be committed at all, it isn't ready and apparently
was in the wrong branch locally.

Binding generators apparently need this as they can't really know
that the callback is guaranteed to be called exactly once and that
the user_data can be freed at the end of it.

Fixes bug #586570.

And deprecate the gulong versions.  This is to support platforms
where sizeof(unsigned long) < sizeof(void *).  Fixes #627565.

API: Add gst_x_overlay_set_window_handle()
API: Deprecate: gst_x_overlay_set_xwindow_id()
API: Add gst_x_overlay_got_window_handle()
API: Deprecate: gst_x_overlay_got_xwindow_id()
API: Add GstXOverlay::set_window_handle()
API: Deprecate: GstXOverlay::set_xwindow_id()

Replace moving-color-bars pattern with smpte100, and change
moving-speed to horizontal-speed.  Default is now 0.  Add
a rotation stage to pattern building.
Allocate a temporary scanline for building images.  Remove
unused code.  Disable several patterns that we're unable to
test and probably never used.  Add other variants of bayer
sampling.  Convert some patterns to use videotestsrc_blend_line.

Scanlines are generated into AYUV/ARGB, then converted to the
various formats.

This pattern is moving the color bars with a given
speed. Negative speed is inverting the moving direction.

https://bugzilla.gnome.org/show_bug.cgi?id=628500

Convert downsampling to Orc.  Convert horizontal linear scaling
to Orc.  Combine horizontal and vertical scaling into one pass.

API: gst_video_convert_frame_async()

Unfortunately this can't test the encoding because there's no
image encoder in base.

There will always be only a single output buffer and if the
target caps have a different framerate than the input there
will be a negotiation error during conversion.

https://bugzilla.gnome.org/show_bug.cgi?id=629157

https://bugzilla.gnome.org/show_bug.cgi?id=629157

Add methods to convert between uri and sdpmessages, loosly based on
http://tools.ietf.org/html/draft-fujikawa-sdp-url-01

API: GstSDPMessage::gst_sdp_message_parse_uri
API: GstSDPMessage::gst_sdp_message_as_uri

Only do wildcard expansion (why?!) on things that look like local
file paths. Fixes passing of URIs containing '*' and '?' (see #629212).

Now one can use GST_NO_STATE_IGNORE_ELEMENTS=1 make generic/states.check
to try elements that would normaly be skipped.