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: We also handle AU alignment
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
openh264enc: Switch to an adapter for the output

Appending too many memories to a buffer is going to be slower
as it will cause copy of the buffer and then appending of the memory.