gl/cocoa: Handle NSView::renewGState() properly

Don't update the screen until we redraw, this prevents flickering during
scrolling, clipping, resizing, etc
gl/cocoa: Always update our viewport if Cocoa tells us something has changed

The visible rect and bounds might be the same as before, but Cocoa
might've changed our viewport without us nothing. This happens if
you hide the view and show it again.
videoaggregator: GstVideoConverter currently can't rescale and will assert

Leads to ugly assertions instead of properly erroring out:
CRITICAL **: gst_video_converter_new: assertion 'in_info->width == out_info->width' failed
videoaggregator: Revert the last commit and handle resolutions differences properly

This is about converting the format, not about converting any widths and
heights. Subclasses are expected to handler different resolutions themselves,
like the videomixers already do properly.
videoaggregator: Also copy over the chroma siting and colorimetry when deciding on a conversion
androidmedia: Fix calculation of the frame size for COLOR_FormatYUV420Planar

https://bugzilla.gnome.org/show_bug.cgi?id=734156
vc1parse: unref caps when it is empty in renegotiate()

https://bugzilla.gnome.org/show_bug.cgi?id=737724
gst: remove unnecessary GLIB_DISABLE_DEPRECATION_WARNINGS

There are unnecessary definitions for disabling deprecation warnings.
Since GLIB_DISABLE_DEPRECATION_WARNINGS is not needed anymore in these files,
removing the same.

https://bugzilla.gnome.org/show_bug.cgi?id=737559
aggregator: Take lock to ensure set_caps is not called concurently

Avoiding to be in an inconsistent state where we do not have
actual negotiate caps set as srccaps and leading to point where we
try to unref ->srccaps when they have already been set to NULL.

https://bugzilla.gnome.org/show_bug.cgi?id=735042
videoaggregator: Do not to release VIDEO_AGGREGATOR_LOCK while setting format info

We should be able to always keep the VIDEO_AGGREGATOR_LOCK while
negotiating caps, this patch introduce that change.

That also implies that we do not need the SETCAPS_LOCK anymore because
now VIDEO_AGGREGATOR_LOCK guarantees that setcaps is not called from
several threads and the gst_aggregator_set_caps method is now
protected.

https://bugzilla.gnome.org/show_bug.cgi?id=735042
openh264: Add OpenH264 based encoder/decoder elements

These are the openh264 elements released under the BSD-2 license
by Ericsson as part of the OpenWebRTC project.
https://github.com/EricssonResearch/openwebrtc-gst-plugins

https://bugzilla.gnome.org/show_bug.cgi?id=737788
openh264dec: Fix input state handling and propagation of upstream caps fields
openh264enc: Don't set caps manually

This will break the order of events in GStreamer.
openh264dec: Remove invalid sprops-parameter-set handling

This only exists on RTP caps, not H264 caps.
openh264dec: Fix various crashes on ::stop()
openh264dec: Don't forget to unref the input state
openh264dec: Optimize frame copying a bit
openh264dec: Add support for GstVideoMeta

This will make operation with various sinks faster for free.
openh264enc: Add support for GstVideoMeta

This will allow upstream elements to work more efficiently.
openh264enc: Fix up caps and stride handling